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  • 151.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Sundell-Bergman, S.
    Swedish Univ Agr Sci, Dept Soil & Environm, Umea, Sweden.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Viberg, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Gordh, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Effects on adult cognitive function after neonatal exposure to clinically relevant doses of ionising radiation and ketamine in mice2018In: British Journal of Anaesthesia, ISSN 0007-0912, E-ISSN 1471-6771, Vol. 120, no 3, p. 546-554Article in journal (Refereed)
    Abstract [en]

    Background: Radiological methods for screening, diagnostics and therapy are frequently used in healthcare. In infants and children, anaesthesia/sedation is often used in these situations to relieve the patients' perception of stress or pain. Both ionising radiation (IR) and ketamine have been shown to induce developmental neurotoxic effects and this study aimed to identify the combined effects of these in a murine model. Methods: Male mice were exposed to a single dose of ketamine (7.5 mg kg(-1) body weight) s.c. on postnatal day 10. One hour after ketamine exposure, mice were whole body irradiated with 50-200 mGy gamma radiation (Cs-137). Behavioural observations were performed at 2, 4 and 5 months of age. At 6 months of age, cerebral cortex and hippocampus tissue were analysed for neuroprotein levels. Results: Animals co-exposed to IR and ketamine displayed significant (P <= 0.01) lack of habituation in the spontaneous behaviour test, when compared with controls and single agent exposed mice. In the Morris Water Maze test, co-exposed animals showed significant (P <= 0.05) impaired learning and memory capacity in both the spatial acquisition task and the relearning test compared with controls and single agent exposed mice. Furthermore, in co-exposed mice a significantly (P <= 0.05) elevated level of tau protein in cerebral cortex was observed. Single agent exposure did not cause any significant effects on the investigated endpoints. Conclusion: Co-exposure to IR and ketamine can aggravate developmental neurotoxic effects at doses where the single agent exposure does not impact on the measured variables. These findings show that estimation of risk after paediatric low-dose IR exposure, based upon radiation dose alone, may underestimate the consequences for this vulnerable population.

  • 152.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Sundell-Bergman, Synnöve
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Developmental coexposure to gamma-radiation and paraquat can exacerbate cognitive dysfunction in adult mice2015Conference paper (Other academic)
  • 153.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Sundell-Bergman, Synnöve
    Sveriges lantbruksuniversitet, Fakulteten för naturresurser och lantbruksvetenskap, Institutionen för Mark och miljö.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Coexposure to gamma-radiation and nicotine during a critical period of neonatal brain development can excarebate cognitive defects in adult mice2014Conference paper (Refereed)
  • 154.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Sundell-Bergman, Synnöve
    Sveriges lantbruksuniversitet, Fakulteten för naturresurser och lantbruksvetenskap, Institutionen för Mark och miljö.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Cognitive defects and tau protein alterations in adult mice following neonatal low dose co-exposure to radiation and ketamine2014Conference paper (Refereed)
  • 155.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Sundell-Bergman, Synnöve
    Sveriges lantbruksuniversitet, Fakulteten för naturresurser och lantbruksvetenskap, Institutionen för Mark och miljö.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Psychiatry, University Hospital.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Exposure to a single dose of ionising radiation during brain development can cause cognitive defects and increased levels of tau in mice2012Conference paper (Refereed)
    Abstract [en]

    Ionising radiation (IR) is widely used in the medical field for treating tumours, including tumours in the central nervous system, and for imaging techniques such as computed tomography (CT). There is a lack of knowledge and increasing concern about effects and consequences from low dose exposure during critical phases of perinatal and/or neonatal brain development compared to prenatal irradiation. It is known that IR causes neurotoxicological and neurobehavioural defects in mammals. Further, an epidemiological study has suggested that low doses of IR to the human brain during infancy can have a negative effect on cognitive abilities in adulthood. The rapid brain growth spurt (BGS) occurs in humans as well as mice. In humans the BGS starts during the third trimester of pregnancy and continues throughout the first two years of life. In mouse and rat the BGS is neonatal, spanning the first 3-4 weeks of life. The BGS is characterized by maturation of axonal and dendritic outgrowth, establishment of neural connections and acquisition of many new motor and sensory abilities. By using the neonatal mouse as an animal model we are able to study the effect of IR during early periods of brain development and which consequences it has for the adult animal. Disturbances in development caused by nicotine, MeHg, PCBs and PBDEs have previously been shown to alter adult spontaneous behaviour and/or neuroprotein levels in mice.

    Neonatal NMRI male mice were irradiated (0; 0.35 and 0.5 Gy) at one single occasion on postnatal day 10. Mice serving as controls were placed in plastic dishes for a time-period corresponding to the irradiation. Spontaneous behaviour was tested in a novel home environment at 2- and 4-months of age and parameters observed were locomotion, rearing and total activity. Analyses of important neuroprotein levels were performed on 6-month-old control and 0.5 Gy irradiated mice.

    Spontaneous behaviour test (locomotion, rearing, total activity revealed a significantly deranged behaviour in 2- and 4-month old mice irradiated with 0.35 or 0.5 Gy in a dose-response related manner, when compared to controls. The behavioural alterations were manifested as a reduced activity during at the beginning of the observational period and a higher activity at the end of the observational period. Analyses of the neuroprotein tau, which in human medicine is used as a biomarker for Alzheimer’s disease, showed a significantly higher level in mice irradiated with 0.5 Gy compared to controls. This demonstrates that a single dose of gamma radiation, given at a defined critical time period during brain development, is sufficient to cause persistently reduced cognitive functions and increased levels of tau in mice.   

  • 156.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Sundell-Bergman, Synnöve
    Sveriges lantbruksuniversitet, Fakulteten för naturresurser och lantbruksvetenskap, Institutionen för Mark och miljö.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Viberg, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Neonatal exposure to a single low dose of ionising radiation causes persistent disruptions in cognitive abilities and increased levels of tau in mice2013Conference paper (Other academic)
    Abstract [en]

    Ionising radiation (IR) is extensively used in the medical field for treatment and diagnostics. Concern has been raised about possible negative consequences from low dose exposure to IR during critical phases of perinatal and/or neonatal brain development. The brain growth spurt, which is characterized by maturation of axonal and dendritic outgrowth, establishment of neural connections and acquisition of new motor and sensory abilities, occurs perinatally in humans and neonatally in mice. By using the neonatal mouse as an animal model we are able to study the effect of IR during early periods of brain development and which consequences it has for the adult animal.

    Neonatal NMRI mice were irradiated (0; 0.35 and 0.5 Gy) at one single occasion on postnatal day 10. At 2- and 4-months of age, spontaneous behaviour was tested in a novel home environment and parameters observed were locomotion, rearing and total activity. Analyses of important neuroproteins in cerebral cortex were performed 24h following irradiation (0 and 0.5 Gy) and at 6-months of age.

    Observations of spontaneous behaviour revealed a significantly deranged behaviour in 2- and 4-month old mice of both sexes irradiated with 0.35 or 0.5 Gy in a dose response related manner. The observed reduced activity during the beginning of the test period and increased activity at the end of the test period indicates a lack of habituation capacity and disrupted cognitive functions. Neuroprotein analyses of cerebral cortex 24h after irradiation and at 6-months of age showed a significantly increased level of tau in mice irradiated with 0.5 Gy compared to controls. This demonstrates that a single dose of IR, given at a defined critical period during brain development, is sufficient to cause persistently reduced cognitive functions and increased levels of tau in mice. 

  • 157.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Sundell-Bergman, Synnöve
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Viberg, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Gordh, Torsten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Ketamine interacts with low dose ionizing radiaiton during brain development to impair cognitive function in mouse2016In: Anesthesiology, ISSN 0003-3022, E-ISSN 1528-1175Article in journal (Refereed)
  • 158.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Viberg, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Developmental exposure to PBDE 209: sex, neuroprotein and neurobehavioural analyses2012In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 211, no supplement, p. S90-Article in journal (Refereed)
    Abstract [en]

    Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame-retardants in polymers products.Newborns and toddlers can be indirectly and directly exposed to PBDEs during a period of critical rapid brain development. The present study was undertaken to investigate neurotoxic effects after neonatal exposure to PBDE 209 on sex differences, cognitive function, neuroproteins and altered susceptibility to toxicants in adults.

     

    3-day-old NMRI mice were exposed to PBDE 209 (2,2´,3,3´,4,4´,5,5´,6,6´-decaBDE at 0, 1.4, 6.0 and 14 µmol/kg bw). At 2 months of age male mice were exposed to paraoxon (0.25 mg/kg bw, every 2nd day for 7 days) and female mice exposed to nicotine (80 µg nicotine base/kg bw). At the age of 2 and 4 months mice were observed for spontaneous behaviour, before and after adult exposure to paraoxon (male) and nicotine (female). Male mice aged 5 and 7 months were observed for memory and learning. Neuroproteins CaMKII, GAP-43, synaptophysin and tau in cerebral cortex and hippocampus from 7-months old male and female mice were analyzed.

     

    The present study shows that neonatal exposure to PBDE 209 can induce developmental neurobehavioural defects in both male and female mice. Neonatal exposure to PBDE 209 also caused increased susceptibility in adult mice to paraoxon and nicotine. All these effects were dose response related. Further, neonatal exposure to PBDE 209 caused persistent defects in memory and learning in adult male mice and increased levels of important neuroproteins e.g. tau in adult male and female mice.

  • 159.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Viberg, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Developmental exposure to the polybrominated diphenyl ether PBDE 209: Neurobehavioural and neuroprotein analysis in adult male and female mice2014In: Environmental Toxicology and Pharmacology, ISSN 1382-6689, E-ISSN 1872-7077, Vol. 38, no 2, p. 570-585Article in journal (Refereed)
    Abstract [en]

    Polybrominated diphenyl ethers (PBDEs), used as flame retardants in polymer products, are reported to cause developmental neurotoxic effects in mammals. The present study have investigated neurotoxic effects arising from neonatal exposure to PBDE 209, including alterations in sex differences, spontaneous behaviour, learning and memory, neuroproteins and altered susceptibility of the cholinergic system in adults. Three-day-old NMRI mice, of both sexes, were exposed to PBDE 209 (2,2',3,3',4,4',5,5',6,6'-decaBDE at 0, 1.4, 6.0 and 14.0 mu mol/kg b.w.). At adult age (2-7 months) a similar developmental neurotoxic effects in both male and female mice were seen, including lack of or reduced habituation to a novel home environment, learning and memory defects, modified response to the cholinergic agent's paraoxon (males) and nicotine (females) indicating increased susceptibility of the cholinergic system. The behavioural defects were dose-response related and persistent. In mice of both sexes and showing behavioural defects, neuroprotein tau was increased. (C) 2014 Elsevier B.V. All rights reserved.

  • 160.
    Buratovic, Sonja
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Viberg, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Fredriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Eriksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Developmental exposure to the polybrominated diphenylether PBDE 209: Neurobehavioural and neuroprotein analysis in adult male and female mice2014In: Environmental Toxicology and Pharmacology, ISSN 1382-6689, E-ISSN 1872-7077, Vol. 38, p. 570-585Article in journal (Refereed)
    Abstract [en]

    Polybrominated diphenyl ethers (PBDEs), used as flame retardants in polymer products,are reported to cause developmental neurotoxic effects in mammals. The present studyhave investigated neurotoxic effects arising from neonatal exposure to PBDE 209, includingalterations in sex differences, spontaneous behaviour, learning and memory, neuroproteinsand altered susceptibility of the cholinergic system in adults.Three-day-old NMRI mice, of both sexes, were exposed to PBDE 209 (2,2,3,3,4,4,5,5,6,6-decaBDE at 0, 1.4, 6.0 and 14.0 mol/kg b.w.). At adult age (2–7 months) a similardevelopmental neurotoxic effects in both male and female mice were seen, including lackof or reduced habituation to a novel home environment, learning and memory defects,modified response to the cholinergic agent’s paraoxon (males) and nicotine (females) indi-cating increased susceptibility of the cholinergic system. The behavioural defects weredose–response related and persistent. In mice of both sexes and showing behaviouraldefects, neuroprotein tau was increased.

  • 161.
    Burki, Fabien
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    A new Lineage of Eukaryotes Illuminates Eraly Mitochondrial Genome Reduction2017In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445Article in journal (Refereed)
  • 162.
    Burki, Fabien
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. Uppsala Univ, Dept Organismal Biol, Program Systemat Biol, Sci Life Lab, Norbyvagen 18D, S-75236 Uppsala, Sweden..
    Mitochondrial Evolution: Going, Going, Gone2016In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 26, no 10, p. R410-R412Article in journal (Other academic)
    Abstract [en]

    Monocercomonoides is the first example of a eukaryote lacking even the most reduced form of a mitochondrion-related organelle. This has important implications for cellular processes and our understanding of reductive mitochondrial evolution across the eukaryotic tree of life.

  • 163.
    Burki, Fabien
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    The Convoluted Evolution of Eukaryotes With Complex Plastids2017In: Secondary Endosymbioses / [ed] Yoshihisa Hirakawa, Elsevier, 2017, p. 1-30Chapter in book (Other academic)
    Abstract [en]

    The textbook version of how plastids were established by endosymbiosis and subsequently diversified is like a well-oiled machine: a cyanobacterial endosymbiont was taken up by a heterotrophic cell and transformed over time into a bona fide photosynthetic organelle (plastid), ultimately giving rise to all plants and algae. The reality, however, is much more complicated and this chapter attempts to describe recent advances in the field of plastid evolution brought to light by disciplines such as phylogenomics, comparative genomics, and cell biology. If (almost) all plastids may ultimately trace back to the same original endosymbiotic event, the very large diversity of plastids we observe today can only be explained by multiple layers of endosymbioses. That is, plastids were passed between distantly related eukaryotic lineages multiple times, essentially creating a phylogenetic imbroglio where plastids appear monophyletic but hosts are not. The burning question then is: how can we best fit plastid and host data into a comprehensive evolutionary framework? Focusing not only on the so-called complex plastids (the product of eukaryote-to-eukaryote endosymbioses) and the lineages that host them but also on the many related plastid-lacking lineages and orphan taxa, I discuss the emergence of new models of plastid evolution. These models generalize the notion of serial endosymbioses to explain the scattered distribution of plastids in the eukaryotic tree of life. As such, they make new testable predictions as to how complex algae are connected through endosymbiotic gene transfer, but testing this will require first to determine the real magnitude of this process.

  • 164.
    Burraco, Pablo
    et al.
    CSIC, Donana Biol Stn, Dept Wetland Ecol, Ecol Evolut & Dev Grp, E-41092 Seville, Spain..
    Valdes, Ana Elisa
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany. Stockholm Univ, Dept Ecol Environm & Plant Sci, SE-10691 Stockholm, Sweden..
    Johansson, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Gomez-Mestre, Ivan
    CSIC, Donana Biol Stn, Dept Wetland Ecol, Ecol Evolut & Dev Grp, E-41092 Seville, Spain..
    Physiological mechanisms of adaptive developmental plasticity in Rana temporaria island populations2017In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 17, article id 164Article in journal (Refereed)
    Abstract [en]

    Background: Adaptive plasticity is essential for many species to cope with environmental heterogeneity. In particular, developmental plasticity allows organisms with complex life cycles to adaptively adjust the timing of ontogenetic switch points. Size at and time to metamorphosis are reliable fitness indicators in organisms with complex cycles. The physiological machinery of developmental plasticity commonly involves the activation of alternative neuroendocrine pathways, causing metabolic alterations. Nevertheless, we have still incomplete knowledge about how these mechanisms evolve under environments that select for differences in adaptive plasticity. In this study, we investigate the physiological mechanisms underlying divergent degrees of developmental plasticity across Rana temporaria island populations inhabiting different types of pools in northern Sweden. Methods: In a laboratory experiment we estimated developmental plasticity of amphibian larvae from six populations coming from three different island habitats: islands with only permanent pools, islands with only ephemeral pools, and islands with a mixture of both types of pools. We exposed larvae of each population to either constant water level or simulated pool drying, and estimated their physiological responses in terms of corticosterone levels, oxidative stress, and telomere length. Results: We found that populations from islands with only temporary pools had a higher degree of developmental plasticity than those from the other two types of habitats. All populations increased their corticosterone levels to a similar extent when subjected to simulated pool drying, and therefore variation in secretion of this hormone does not explain the observed differences among populations. However, tadpoles from islands with temporary pools showed lower constitutive activities of catalase and glutathione reductase, and also showed overall shorter telomeres. Conclusions: The observed differences are indicative of physiological costs of increased developmental plasticity, suggesting that the potential for plasticity is constrained by its costs. Thus, high levels of responsiveness in the developmental rate of tadpoles have evolved in islands with pools at high but variable risk of desiccation. Moreover, the physiological alterations observed may have important consequences for both short-term odds of survival and long term effects on lifespan.

  • 165.
    Bálint, Miklós
    et al.
    Senckenberg Biodivers & Climate Res Ctr, Senckenberganlage 25, D-60325 Frankfurt, Germany.
    Bahram, Mohammad
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. Univ Tartu, Inst Ecol & Earth Sci, Dept Bot, 40 Lai St, EE-51005 Tartu, Estonia.
    Eren, A. Murat
    Marine Biol Lab, Josephine Bay Paul Ctr Comparat Mol Biol & Evolut, Woods Hole, MA 02543 USA; Univ Chicago, Dept Med, 5841 S Maryland Ave, Chicago, IL 60637 USA.
    Faust, Karoline
    Katholieke Univ Leuven, Rega Inst, Ctr Biol Dis, B-3000 Leuven, Belgium.
    Fuhrman, Jed
    Univ Southern Calif, Dept Biol Sci, MC0371, Los Angeles, CA 90089 USA.
    Lindahl, Björn
    Swedish Univ Agr Sci, Dept Soil & Environm, Box 7014, SE-75007 Uppsala, Sweden.
    O'Hara, Robert B.
    Senckenberg Biodivers & Climate Res Ctr, Senckenberganlage 25, D-60325 Frankfurt, Germany.
    Öpik, Maarja
    Univ Tartu, Inst Ecol & Earth Sci, Dept Bot, 40 Lai St, EE-51005 Tartu, Estonia.
    Sogin, Mitchell L.
    Marine Biol Lab, Josephine Bay Paul Ctr Comparat Mol Biol & Evolut, Woods Hole, MA 02543 USA.
    Untersehe, Martin
    Ernst Moritz Arndt Univ Greifswald, Inst Bot & Landscape Ecol, Soldmannstr 15, D-17487 Greifswald, Germany.
    Tedersoo, Leho
    Univ Tartu, Nat Hist Museum, 14a Ravila St, EE-50411 Tartu, Estonia.
    Millions of reads, thousands of taxa: microbial community structure and associations analyzed via marker genes2016In: FEMS Microbiology Reviews, ISSN 0168-6445, E-ISSN 1574-6976, Vol. 40, no 5, p. 686-700Article in journal (Refereed)
    Abstract [en]

    With high-throughput sequencing (HTS), we are able to explore the hidden world of microscopic organisms to an unpre-cedented level. The fast development of molecular technology and statistical methods means that microbial ecologists must keep their toolkits updated. Here, we review and evaluate some of the more widely adopted and emerging techniques for analysis of diversity and community composition, and the inference of species interactions from co-occurrence data generated by HTS of marker genes. We emphasize the importance of observational biases and statistical properties of the data and methods. The aim of the review is to critically discuss the advantages and disadvantages of established and emerging statistical methods, and to contribute to the integration of HTS-based marker gene data into community ecology.

  • 166.
    Campione, Nicolas E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Evans, David C.
    Brown, Caleb M.
    Carrano, Matthew T.
    Body mass estimation in non-avian bipeds using a theoretical conversion to quadruped stylopodial proportions2014In: Methods in Ecology and Evolution, ISSN 2041-210X, E-ISSN 2041-210X, Vol. 5, no 9, p. 913-923Article in journal (Refereed)
    Abstract [en]

    Body mass is strongly related to both physiological and ecological properties of living organisms. As a result, generating robust, broadly applicable models for estimating body mass in the fossil record provides the opportunity to reconstruct palaeobiology and investigate evolutionary ecology on a large temporal scale. A recent study provided strong evidence that the minimum circumference of stylopodial elements (humerus and femur) is conservatively associated with body mass in living quadrupeds. Unfortunately, this model is not directly applicable to extinct bipeds, such as non-avian dinosaurs. This study presents a new equation that mathematically corrects the quadruped equation for use in bipeds. It is derived from the systemic difference in the circumference-to-area scaling relationship of two circles (hypothetical quadruped) and one circle (hypothetical biped), which represent the cross-section of the main weight-bearing limb bones. When applied to a newly constructed data set of femoral circumferences and body masses in living birds, the new equation reveals errors that are significantly lower than other published equations, but significantly higher than the error inherent in the avian data set. Such errors, however, are expected given the unique overall femoral circumference-body mass scaling relationship found in birds. Body mass estimates for a sample of bipedal dinosaurs using the new model are consistent with recent estimates based on volumetric life reconstructions, but, in contrast, this equation is simpler to use, with the concomitant potential to provide a wider set of body mass estimates for extinct bipeds. Although it is evident that no one estimation model is flawless, the combined use of the corrected quadrupedal equations and the previously published quadrupedal equation offer a consistent approach with which to estimate body masses in both quadrupeds and bipeds. These models have implications for conducting large-scale macroevolutionary analyses of body size throughout the evolutionary history of terrestrial vertebrates, and, in particular, across major changes in body plan, such as the evolution of bipedality in archosaurs and quadrupedality in dinosaurs.

  • 167.
    Capuccini, Marco
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computational Science. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Larsson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Carone, Matteo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Novella, Jon Ander
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Sadawi, Noureddin
    Gao, Jianliang
    Toor, Salman
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computational Science. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing.
    Spjuth, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences. Uppsala University, Science for Life Laboratory, SciLifeLab.
    On-demand virtual research environments using microservices2019In: PeerJ Computer Science, ISSN 2376-5992, Vol. 5, article id e232Article in journal (Refereed)
    Abstract [en]

    The computational demands for scientific applications are continuously increasing. The emergence of cloud computing has enabled on-demand resource allocation. However, relying solely on infrastructure as a service does not achieve the degree of flexibility required by the scientific community. Here we present a microservice-oriented methodology, where scientific applications run in a distributed orchestration platform as software containers, referred to as on-demand, virtual research environments. The methodology is vendor agnostic and we provide an open source implementation that supports the major cloud providers, offering scalable management of scientific pipelines. We demonstrate applicability and scalability of our methodology in life science applications, but the methodology is general and can be applied to other scientific domains.

  • 168. Caputo, Beniamino
    et al.
    Santolamazza, Federica
    Vicente, Jose L.
    Nwakanma, Davis C.
    Jawara, Musa
    Pålsson, Katinka
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Systematic Biology.
    Jaenson, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Systematic Biology.
    White, Bradley J.
    Mancini, Emiliano
    Petrarca, Vincenzo
    Conway, David J.
    Besansky, Nora J.
    Pinto, Joao
    della Torre, Alessandra
    The "Far-West'' of Anopheles gambiae Molecular Forms2011In: PLoS ONE, ISSN 1932-6203, Vol. 6, no 2, p. e16415-Article in journal (Refereed)
    Abstract [en]

    The main Afrotropical malaria vector, Anopheles gambiae sensu stricto, is undergoing a process of sympatric ecological diversification leading to at least two incipient species (the M and S molecular forms) showing heterogeneous levels of divergence across the genome. The physically unlinked centromeric regions on all three chromosomes of these closely related taxa contain fixed nucleotide differences which have been found in nearly complete linkage disequilibrium in geographic areas of no or low M-S hybridization. Assays diagnostic for SNP and structural differences between M and S forms in the three centromeric regions were applied in samples from the western extreme of their range of sympatry, the only area where high frequencies of putative M/S hybrids have been reported. The results reveal a level of admixture not observed in the rest of the range. In particular, we found: i) heterozygous genotypes at each marker, although at frequencies lower than expected under panmixia; ii) virtually all possible genotypic combinations between markers on different chromosomes, although genetic association was nevertheless detected; iii) discordant M and S genotypes at two X-linked markers near the centromere, suggestive of introgression and inter-locus recombination. These results could be indicative either of a secondary contact zone between M and S, or of the maintenance of ancestral polymorphisms. This issue and the perspectives opened by these results in the study of the M and S incipient speciation process are discussed.

  • 169.
    Cardenas, Paco
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Rapp, Hans Tore
    Disrupted spiculogenesis in deep-water Geodiidae (Porifera, Demospongiae) growing in shallow waters2013In: Invertebrate biology., ISSN 1077-8306, E-ISSN 1744-7410, Vol. 132, no 3, p. 173-194Article in journal (Refereed)
    Abstract [en]

    Environmental conditions can affect the morphology and distribution of sponges. In particular, depth is known to influence the morphology of shallow-water sponges; however, the influence of depth on deep-water sponges has never been investigated. Although boreal Geodiidae (Demospongiae, Astrophorida) are deep-water species, in fjords and along the Norwegian coast Geodia barretti, G. simplicissima, and Pachymatisma normani can occasionally be found at shallow depths (20-40m). In this study, we examine new shallow specimens from the Norwegian coast to compare their morphological and molecular characteristics with those of their deep-water counterparts. Morphology was studied at the level of the organism, skeletal organization, and the spicules, and a fragment of the cytochrome oxidase 1 gene was sequenced for shallow and deep specimens. Twelve specimens of Geodia spp. and five specimens of P. normani were collected in shallow waters. The majority of the Geodia spp. were identified as G. simplicissima, a species that has not been reported since its original description in 1931. However, we propose that G. simplicissima, only found in shallow waters, is a junior synonym of G. barretti. When comparing shallow and deep-water specimens of G. barretti and P. normani, we found phenotypic differences with respect to color, external morphology, cortex organization, and, above all, spicule morphology. In shallow specimens, microrhabds, sterrasters, and triaenes were smaller and irregular or underdeveloped. Oxyasters and strongylasters were normal in form, but smaller. We hypothesize that the lower silica concentration in shallow waters is primarily responsible for the disruption of spiculogenesis in shallow-water specimens of G. barretti and P. normani. The underdeveloped sterrasters observed in shallow-water specimens provide new insights into the formation of these particular microscleres. Finally, we discuss how the colonization of shallow waters by deep-water sponges may have strongly influenced spicule evolution and speciation.

  • 170.
    Cardenas, Paco
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Rapp, Hans Tore
    Klitgaard, Anne Birgitte
    Best, Megan
    Thollesson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Tendal, Ole Secher
    Taxonomy, biogeography and DNA barcodes of Geodia species (Porifera, Demospongiae, Tetractinellida) in the Atlantic boreo-arctic region2013In: Zoological Journal of the Linnean Society, ISSN 0024-4082, E-ISSN 1096-3642, Vol. 169, no 2, p. 251-311Article in journal (Refereed)
    Abstract [en]

    Geodia species north of 60 degrees N in the Atlantic appeared in the literature for the first time when Bowerbank described Geodia barretti and G.macandrewii in 1858 from western Norway. Since then, a number of species have been based on material from various parts of the region: G.simplex, Isops phlegraei, I.pallida, I.sphaeroides, Synops pyriformis, G.parva, G.normani, G.atlantica, Sidonops mesotriaena (now called G.hentscheli), and G.simplicissima. In addition to these 12 nominal species, four species described from elsewhere are claimed to have been identified in material from the northeast Atlantic, namely G.nodastrella and G.cydonium (and its synonyms Cydonium muelleri and Geodia gigas). In this paper, we revise the boreo-arctic Geodia species using morphological, molecular, and biogeographical data. We notably compare northwest and northeast Atlantic specimens. Biological data (reproduction, biochemistry, microbiology, epibionts) for each species are also reviewed. Our results show that there are six valid species of boreo-arctic Atlantic Geodia while other names are synonyms or mis-identifications. Geodia barretti, G.atlantica, G.macandrewii, and G.hentscheli are well established and widely distributed. The same goes for Geodia phlegraei, but this species shows a striking geographical and bathymetric variation, which led us to recognize two species, G.phlegraei and G.parva (here resurrected). Some Geodia are arctic species (G.hentscheli, G.parva), while others are typically boreal (G.atlantica, G.barretti, G.phlegraei, G.macandrewii). No morphological differences were found between specimens from the northeast and northwest Atlantic, except for G.parva. The Folmer cytochrome oxidase subunit I (COI) fragment is unique for every species and invariable over their whole distribution range, except for G.barretti which had two haplotypes. 18S is unique for four species but cannot discriminate G.phlegraei and G.parva. Two keys to the boreo-arctic Geodia are included, one based on external morphology, the other based on spicule morphology.

  • 171.
    Carlsbecker, Annelie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany.
    Sundstrom, Jens F.
    Englund, Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany.
    Uddenberg, Daniel
    Izquierdo, Liz
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Kvarnheden, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Vergara-Silva, Francisco
    Engström, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany.
    Molecular control of normal and acrocona mutant seed cone development in Norway spruce (Picea abies) and the evolution of conifer ovule-bearing organs2013In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 200, no 1, p. 261-275Article in journal (Refereed)
    Abstract [en]

    Reproductive organs in seed plants are morphologically divergent and their evolutionary history is often unclear. The mechanisms controlling their development have been extensively studied in angiosperms but are poorly understood in conifers and other gymnosperms. Here, we address the molecular control of seed cone development in Norway spruce, Picea abies. We present expression analyses of five novel MADS-box genes in comparison with previously identified MADS and LEAFY genes at distinct developmental stages. In addition, we have characterized the homeotic transformation from vegetative shoot to female cone and associated changes in regulatory gene expression patterns occurring in the acrocona mutant. The analyses identified genes active at the onset of ovuliferous and ovule development and identified expression patterns marking distinct domains of the ovuliferous scale. The reproductive transformation in acrocona involves the activation of all tested genes normally active in early cone development, except for an AGAMOUS-LIKE6/SEPALLATA (AGL6/SEP) homologue. This absence may be functionally associated with the nondeterminate development of the acrocona ovule-bearing scales. Our morphological and gene expression analyses give support to the hypothesis that the modern cone is a complex structure, and the ovuliferous scale the result of reductions and compactions of an ovule-bearing axillary short shoot in cones of Paleozoic conifers.

  • 172.
    Carlsbecker, Annelie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany.
    Sundström, Jens
    Tandre, Karolina
    Englund, Marie
    Kvarnheden, Anders
    Johansson, Urban
    Engström, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany.
    The DAL10 gene from Norway spruce (Picea abies) belongs to a potentially gymnosperm-specific subclass of MADS-box genes and is specifically active in seed cones and pollen cones.2003In: Evolution & Development, Vol. 5, no 6, p. 551-561Article in journal (Refereed)
  • 173.
    Carlsbecker, Annelie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany. Fysiologisk botanik.
    Tandre, Karolina
    Johansson, Urban
    Englund, Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany. Fysiologisk botanik.
    Engström, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Physiological Botany. Fysiologisk botanik.
    The MADS-box gene DAL1 is a potential mediator of the juvenile-to-adult transition in Norway spruce (Picea abies)2004In: The Plant Journal, Vol. 40, p. 546-557Article in journal (Refereed)
    Abstract [en]

    Progression through the plant life cycle involves changes in many essential features, most notably in the capacity to reproduce. The transition from juvenile vegetative and non-reproductive to an adult reproductive phase is gradual and can take many years; in the conifer Norway spruce, Picea abiea, typically 20-25 years. We present a detailed analysis of the activities of three regulatory genes with potential roles in the transition in Norway spruce: DAL1, a MADS-box gene related to the AGL6 group of genes from angiosperms, and the two LEAFY-related genes PaLFY and PaNLY. DAL1 activity is initiated in the shoots of juvenile trees at an age of 3-5 years, and then increases with age, whereas both LFY genes are active throughout the juvenile phase. The activity of DAL1 further shows a spatial pattern along the stem of the tree that parallels a similar gradient in physiolpoical and morphological features associated with maturation to the adult phase. Constitutive expression of DAL1 in transgenic Arabidopsis plants caused a dramatic attenuation of both juvenile and adult growth phases;flowers forming immediately after the embryogenic phase of development in severely affected plants. Taken together, our resulsts support the notion that DAL1 may have a regulatory role in the juvenile-to-adult transition in Norway spruce.

  • 174. Carr, M.
    et al.
    Leadbeater, B. S. C.
    Hassan, R.
    Nelson, M.
    Baldauf, Sandra L.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Molecular phylogeny of choanoflagellates, the sister group to Metazoa2008In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 105, no 43, p. 16641-16646Article in journal (Refereed)
    Abstract [en]

    Choanoflagellates are single-celled aquatic flagellates with a unique morphology consisting of a cell with a single flagellum surrounded by a "collar" of microvilli. They have long interested evolutionary biologists because of their striking resemblance to the collared cells (choanocytes) of sponges. Molecular phylogeny has confirmed a close relationship between choanoflagellates and Metazoa, and the first choanoflagellate genome sequence has recently been published. However, molecular phylogenetic studies within choanoflagellates are still extremely limited. Thus, little is known about choanoflagellate evolution or the exact nature of the relationship between choanoflagellates and Metazoa. We have sequenced four genes from a broad sampling of the morphological diversity of choanoflagellates including most species currently available in culture. Phylogenetic analyses of these sequences, alone and in combination, reject much of the traditional taxonomy of the group. The molecular data also strongly support choanoflagellate monophyly rejecting proposals that Metazoa were derived from a true choanoflagellate ancestor. Mapping of a complementary matrix of morphological and ecological traits onto the phylogeny allows a reinterpretation of choanoflagellate character evolution and predicts the nature of their last common ancestor.

  • 175.
    Carr, Martin
    et al.
    Department of Biology, University of York.
    Nelson, Michaela
    Department of Biology, University of York.
    Leadbeater, Barry
    School of Biosciences, University of Birmingham.
    Baldauf, Sandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Systematic Biology.
    Three Families of LTR Retrotransposons are Present in the Genome of the Choanoflagellate Monosiga brevicollis2008In: Protist, ISSN 1434-4610, E-ISSN 1618-0941, Vol. 159, no 4, p. 579-590Article in journal (Refereed)
    Abstract [en]

    The choanoflagellates are a ubiquitous group of nanoflagellates and the sister group of Metazoa. Examination of the initial draft version of the first choanoflagellate genome, that of Monosiga brevicollis, reveals the presence of three novel families of long terminal repeat (LTR) retrotransposons and an apparent absence of non-LTR retrotransposons and transposons. One of the newly discovered LTR families falls in the chromovirus clade of the Ty3/gypsy group while the other two families are closely related members of the Ty1/copia group. Examination of EST sequences and nucleotide analyses show that all three families are transcriptionally active and potentially functional within the genome of M. brevicollis.

  • 176.
    Castellanos, Cesilie Granum
    et al.
    Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, Postboks 8146 Dep, 0033 Oslo, Norway.
    Sorvik, Irene Beate
    Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, Postboks 8146 Dep, 0033 Oslo, Norway.; Department of Pharmaceutical Biosciences, University of Oslo, Postboks 1068 Blindern, 0316 Oslo, Norway.
    Tanum, Marte Bruu
    Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, Postboks 8146 Dep, 0033 Oslo, Norway.; The Climate and Pollution Agency (Klif), Postboks 8100 Dep, 0032 Oslo, Norway.
    Verhaegen, Steven
    Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, Postboks 8146 Dep, 0033 Oslo, Norway.
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Ropstad, Erik
    Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science, Postboks 8146 Dep, 0033 Oslo, Norway.
    Differential effects of the persistent DDT metabolite methylsulfonyl-DDE in nonstimulated and LH-stimulated neonatal porcine Leydig cells2013In: Toxicology and Applied Pharmacology, ISSN 0041-008X, E-ISSN 1096-0333, Vol. 267, no 3, p. 247-255Article in journal (Refereed)
    Abstract [en]

    3-Methylsulfonyl-DDE (MeSO2-DDE) is a potent adrenal toxicant formed from the persistent insecticide DDT. MeSO2-DDE is widely present in human plasma, milk and fat, and in tissues of marine mammals. In the present study, we investigated endocrine-disrupting properties of MeSO2-DDE in primary neonatal porcine Leydig cells. Unstimulated and LH-stimulated cells were exposed to MeSO2-DDE at concentrations ranging from 0.6 to 20 mu M for 48 h. Cell viability, hormone secretion and expression of steroidogenesis related genes were recorded. Secretion of testosterone and estradiol was increased in a concentration-dependent fashion in unstimulated Leydig cells, while in LH-stimulated cells, secretion of testosterone, estradiol and progesterone was decreased. The expression of important steroidogenic genes was down-regulated both in unstimulated and LH-stimulated cells. Notably, no significant impairment of cell viability occurred at any exposure except the highest concentration (20 mu M) in LH-stimulated cells. This indicated that the effects on hormone secretion and gene expression were not caused by cytotoxicity. We conclude that the adrenal toxicant MeSO2-DDE disrupts hormone secretion in a complex fashion in neonatal porcine Leydig cells. The different endocrine responses in unstimulated and LH-stimulated cells imply that the endocrine disruptive activity of MeSO2-DDE is determined by the physiological status of the Leydig cells.

  • 177.
    Cavender, James C.
    et al.
    Ohio Univ, Dept Environm & Plant Biol, Athens, OH 45701 USA..
    Landolt, John C.
    Shepherd Univ, Dept Biol, Shepherdstown, WV 25443 USA..
    Romeralo, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Perrigo, Allison
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Vadell, Eduardo M.
    JF Kennedy Univ, Escuela Farm & Bioquim, Buenos Aires, DF, Argentina..
    Stephenson, Steven L.
    Univ Arkansas, Dept Biol Sci, Fayetteville, AR 72701 USA..
    New species of Polysphondylium from Madagascar2016In: Mycologia, ISSN 0027-5514, E-ISSN 1557-2536, Vol. 108, no 1, p. 80-109Article in journal (Refereed)
    Abstract [en]

    Two series of samples collected for isolation of dictyostelid cellular slime molds (dictyostelids) in Madagascar yielded a relatively large number of isolates of Polysphondylium. Most of these turned out to be species new to science that show varying degrees of clustering from unclustered to coremiform as well as an ability to migrate. Migratory ability (phototaxis) is a common feature of species assigned to Group 2 of the Polysphondylia and is common in the new species from Madagascar. Another common feature, clustering, appears to be a strategy for keeping fruiting bodies erect for a longer time in a climate that is relatively dry, whereas migratory ability may function seasonally when there is more rainfall. Thirteen species are described herein. Each of these is characterized by a particular set of distinguishing features, and collectively they expand our concept of the genus Polysphondylium.

  • 178.
    Cavender, James C.
    et al.
    Ohio Univ, Dept Environm & Plant Biol, Athens, OH 45701 USA.
    Vadell, Eduardo
    Univ Kennedy, Escuela Quim, Fac Ciencias Salud, Buenos Aires, DF, Argentina.
    Landolt, John C.
    Shepherd Univ, Dept Biol, Shepherdstown, WV 25443 USA.
    Stephenson, Steven L.
    Univ Arkansas, Dept Biol Sci, Fayetteville, AR 72701 USA.
    Baldauf, Sandra L.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Roux, Jolanda
    Univ Pretoria, Dept Microbiol & Plant Pathol, Forestry & Agr Inst FABI, Pretoria, South Africa.
    Cavender, Nicole
    N Cavender Morton Arboretum, Lisle, IL 60532 USA.
    Winsett, Katherine E.
    Wake Tech Community Coll, Dept Life Sci, Raleigh, NC 27603 USA.
    New dictyostelid cellular slime molds from South Africa2018In: Phytotaxa, ISSN 1179-3155, E-ISSN 1179-3163, Vol. 383, no 3, p. 233-251Article in journal (Refereed)
    Abstract [en]

    A distributional study of the dictyostelid cellular slime molds (dictyostelids) of South Africa was carried out during 2006 as part of the Global Biodiversity of Eumycetozoans project based at the University of Arkansas and funded by the National Science Foundation Samples of soil/humus collected from 31 study sites yielded a total of 881 clones, with an average density of 210 clones/gram for all samples in which dictyostelids were detected. Eighteen different species were represented by one or more clones, and six of these could not be identified. These six species are described herein as new to science. In addition, information is provided on the ecological distribution of all of the species of dictyostelids now known to occur in South Africa.

  • 179. Cavender, James C.
    et al.
    Vadell, Eduardo M.
    Landolt, John C.
    Winsett, Katherine E.
    Stephenson, Steven L.
    Rollins, Adam W.
    Romeralo, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    New small dictyostelids from seasonal rainforests of Central America2013In: Mycologia, ISSN 0027-5514, E-ISSN 1557-2536, Vol. 105, no 3, p. 610-635Article in journal (Refereed)
    Abstract [en]

    Ten small dictyostelids isolated from samples collected from the surface humus layer of seasonal rainforests of Belize and Guatemala were studied morphologically, and nine were found to represent distinct species, all with an average height of < 2 mm (0.5-3.5 mm). Although their fruiting bodies (sorocarps) closely resemble one another, the nine species differ in their patterns of aggregation, stream pattern, branching development, formation of microcysts, spore shape, presence or absence of spore granules and their distribution, as well as in the shapes and behavior of their sorogens and myxamoebae. These stable morphological features were sufficient to recognize nine new species of small dictyostends, one with two varieties. SSU rDNA sequences were generated for all these new isolates, and phylogenetic analyses of these sequences show these new isolates belong to Dictyostelid group 3. As a result of this and other recent studies, the concept of what constitutes a species in the dictyostelids has become much more restricted and well defined, in as much as some of the morphological and behavioral patterns now being observed were overlooked in the past. The extent, flow direction and conformation of streaming within the group varies from simple aggregation mounds with no streams to short streams, to somewhat longer streams and finally to well developed streams. Each of these is characterized by a particular set of distinguishing features.

  • 180.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Andersson, M. Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, The Linnaeus Centre for Bioinformatics.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Aphanomyces astaci and crustaceans.2009In: Oomycete Genetics and Genomics.: Diversity, Interactions, and Research Tools. / [ed] Kurt Lamour and Sophien Kamoun, Hoboken, New Jersey: John Wiley & Sons, Inc. , 2009, p. 425-433Chapter in book (Other academic)
  • 181.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology. Jämförande fysiologi.
    Bangyeekhun, Eakaphun
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology. Jämförande fysiologi.
    Keyser, Pia
    Söderhäll, Irene
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology. jämförande fysiologi.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology. jämförande fysiologi.
    Host prophenoloxidase expression in freshwater crayfish is linked to increased resistance to the crayfish plague fungus, Aphanomyces astaci.2003In: Cell Microbiol, ISSN 1462-5814, Vol. 5, no 5, p. 353-7Article in journal (Refereed)
  • 182.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Haipeng, Liu
    State Key Laboratory of Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen, 361005 Fujian, China.
    Zhang, Yanjiao
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology.
    Rimphanitchayakit, Vichien
    Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
    Tassanakajon, Anchalee
    Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
    Andersson, M. Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, The Linnaeus Centre for Bioinformatics.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Söderhäll, Irene
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    High sequence variability among hemocyte-specific Kazal-type proteinase inhibitors in decapod crustaceans2010In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 34, no 1, p. 69-75Article in journal (Refereed)
    Abstract [en]

    Crustacean hemocytes were found to produce a large number of transcripts coding for Kazal-type proteinase inhibitors (KPIs). A detailed study performed with the crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon revealed the presence of at least 26 and 20 different Kazal domains from the hemocyte KPIs, respectively. Comparisons with KPIs from other taxa indicate that the sequences of these domains evolve rapidly. A few conserved positions, e.g. six invariant cysteines were present in all domain sequences whereas the position of P1 amino acid, a determinant for substrate specificity, varied highly. A study with a single crayfish animal suggested that even at the individual level considerable sequence variability among hemocyte KPIs produced exist. Expression analysis of four crayfish KPI transcripts in hematopoietic tissue cells and different hemocyte types suggest that some of these KPIs are likely to be involved in hematopoiesis or hemocyte release as they were produced in particular hemocyte types or maturation stages only.

  • 183.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Jiravanichpaisal, Pikul
    Liu, Hai-peng
    Söderhäll, Irene
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Crustacean Immunity2010In: Advances in Experimental Medicine and Biology, ISSN 0065-2598, E-ISSN 2214-8019, Vol. 708, p. 239-259Article in journal (Refereed)
    Abstract [en]

    This chapter provides a review of recent progress in the elucidation of innate immune mechanisms in crustaceans. Mainly due to the importance of crustacean aquaculture interest in this field is large and the subject for extensive research efforts. Here, we provide detailed data on the molecular characterisation of lectins, antiviral reactions, hemocyte formation and differentiation and on the regulation of innate immune pathways.

  • 184.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Kawabata, Shun-ichiro
    Lee, Bok Luel
    Nonaka, Masaru
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Proteolytic cascades and their involvement in invertebrate immunity2010In: TIBS -Trends in Biochemical Sciences. Regular ed., ISSN 0968-0004, E-ISSN 1362-4326, Vol. 35, no 10, p. 575-583Article, review/survey (Refereed)
    Abstract [en]

    Bacteria and other potential pathogens are cleared rapidly from the body fluids of invertebrates by the immediate response of the innate immune system. Proteolytic cascades, following their initiation by pattern recognition proteins, control several such reactions, notably coagulation, melanisation, activation of the Toll receptor and complement-like reactions. However, there is considerable variation among invertebrates and these cascades, although widespread, are not present in all phyla. In recent years, significant progress has been made in identifying and characterizing these cascades in insects. Notably, recent work has identified several connections and shared principles among the different pathways, suggesting that cross-talk between them may be common.

  • 185.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Kawabata, Shun-ichiro
    Kyushu University, Fukuoka, Japan.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Biological and Immunological Aspects of Innate Defence Mechanisms Activated by (1,3)- β -Glucans and Related Polysaccharides in Invertebrates2009In: Chemistry, Biochemistry and Biology of (1-›3)-β-Glucans and Related Polysaccharides. / [ed] Antony Bacic, Geoffrey B. Fincher & Bruce A. Stone, Burlington, MA: Academic Press , 2009, p. 563-577Chapter in book (Other academic)
    Abstract [en]

    (1,3)- β -glucans are powerful stimulants of a wide variety of innate defence reactions in invertebrates. These polysaccharides exert a great influence on reactions such as induction of antimicrobial peptides, cellular defence such as encapsulation and phagocytosis, and on the melanization and coagulation cascades. In most cases, these reactions set up an effective defence against microorganisms containing (1,3)- β -glucans or (1,3;1,6)- β -glucans in their outer structures (i.e. mainly fungi and oomycetes).

     

  • 186.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Söderhäll, Kenneth
    Arthropoda:: Pattern recognition proteins in crustacean immunity2018In: Advances in Comparative Immunology, Springer, 2018Chapter in book (Other academic)
  • 187.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Coagulation in invertebrates2011In: Journal of Innate Immunity, ISSN 1662-811X, Vol. 3, no 1, p. 3-8Article, review/survey (Refereed)
    Abstract [en]

    In most animals there is a need to quickly prevent the loss of blood or equivalent fluids through inflicted injuries. In invertebrates with an open circulatory system (and sometimes a hydroskeleton as well) these losses may otherwise soon be fatal. Also, there is a need to prevent microbes that have gained access to the body through the wound from disseminating throughout the open circulatory system. Therefore, many invertebrates possess a coagulation system to prevent such accidents from having too serious consequences. In this review we discuss recent developments in a few animals - mainly arthropods - where more detailed data are available. It is likely, however, that corresponding systems are present in most phyla, but this is still unchartered territory.

  • 188.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Commentary: variable immune molecules in invertebrates2013In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 216, no 23, p. 4313-4319Article in journal (Other academic)
    Abstract [en]

    Recently it has become evident that invertebrates may mount a highly variable immune response that is dependent on which pathogen is involved. The molecular mechanisms behind this diversity are beginning to be unravelled and in several invertebrate taxa immune proteins exhibiting a broad range of diversity have been found. In some cases, evidence has been gathered suggesting that this molecular diversity translates into the ability of an affected invertebrate to mount a defence that is specifically aimed at a particular pathogen.

  • 189.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Crayfish immunity: Recent findings2018In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 80, p. 94-98Article in journal (Refereed)
    Abstract [en]

    Freshwater crayfish is an important commodity as well as a successful model for studies on crustacean immunity. Due to the ease with which they are kept and the available methods for hemocyte separation and culture they have proven to be very useful. Here, recent progress regarding pattern recognition, immune effector production and antiviral mechanisms are discussed. Several cases of functional resemblance between vertebrate complement and the crayfish immune reactions are highlighted.

  • 190.
    Cerenius, Lage
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Söderhäll, Kenneth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Crustacean immune responses and their implications for disease control2012In: Infectious disease in aquaculture: prevention and control / [ed] Austin, B., Cambridge: Woodhead Publishing Limited, 2012, p. 69-87Chapter in book (Refereed)
    Abstract [en]

    This chapter reviews recent advances in our knowledge of crustacean immunity. Emphasis is given to shrimp due to their importance in aquaculture and trade and to freshwater crayfish since they serve as model organisms for research in crustacean immunology. Crustaceans lack antibodies, interferon and some other components from the mammalian immune arsenal but can still mount an efficient defence against many potential pathogens. Crustacean innate immunity relies on a combination of efficient hemocyte and humoral reactions carried out by plasma proteins.

  • 191. Chalopin, Domitille
    et al.
    Volff, Jean-Nicolas
    Galiana, Delphine
    Anderson, Jennifer L
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Schartl, Manfred
    Transposable elements and early evolution of sex chromosomes in fish2015In: Chromosome Research, ISSN 0967-3849, E-ISSN 1573-6849, Vol. 23, no 3, p. 545-560Article in journal (Refereed)
    Abstract [en]

    In many organisms, the sex chromosome pair can be recognized due to heteromorphy; the Y and W chromosomes have often lost many genes due to the absence of recombination during meiosis and are frequently heterochromatic. Repetitive sequences are found at a high proportion on such heterochromatic sex chromosomes and the evolution and emergence of sex chromosomes has been connected to the dynamics of repeats and transposable elements. With an amazing plasticity of sex determination mechanisms and numerous instances of independent emergence of novel sex chromosomes, fish represent an excellent lineage to investigate the early stages of sex chromosome differentiation, where sex chromosomes often are homomorphic and not heterochromatic. We have analyzed the composition, distribution, and relative age of TEs from available sex chromosome sequences of seven teleost fish. We observed recent bursts of TEs and simple repeat accumulations around young sex determination loci. More strikingly, we detected transposable element (TE) amplifications not only on the sex determination regions of the Y and W sex chromosomes, but also on the corresponding regions of the X and Z chromosomes. In one species, we also clearly demonstrated that the observed TE-rich sex determination locus originated from a TE-poor genomic region, strengthening the link between TE accumulation and emergence of the sex determination locus. Altogether, our results highlight the role of TEs in the initial steps of differentiation and evolution of sex chromosomes.

  • 192. Chang, Yue
    et al.
    Liu, Guanglong
    Guo, Lina
    Liu, Hongbo
    Yuan, Dongxia
    Xiong, Jie
    Ning, Yingzhi
    Fu, Chengjie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Miao, Wei
    Cd-Metallothioneins in Three Additional Tetrahymena Species: Intragenic Repeat Patterns and Induction by Metal Ions2014In: Journal of Eukaryotic Microbiology, ISSN 1066-5234, E-ISSN 1550-7408, Vol. 61, no 4, p. 333-342Article in journal (Refereed)
    Abstract [en]

    Ciliate metallothioneins (MTs) possess many unique features compared to the "classic" MTs in other organisms, but they have only been studied in a small number of species. In this study, we investigated cDNAs encoding subfamily 7a metallothioneins (CdMTs) in three Tetrahymena species (T. hegewischi, T. malaccensis, and T. mobilis). Four CdMT genes (ThegMT1, ThegMT2, TmalMT1, and TmobMT1) were cloned and characterized. They share high sequence similarity to previously identified subfamily 7a MT members. Tetrahymena CdMTs exhibit a remarkably regular intragenic repeat homology. The CdMT sequences were divided into two main types of modules, which had been previously described, and which we name "A" and "B". ThegMT2 was identified as the first MT isoform solely composed of module "B". A phylogenetic analysis of individual modules of every characterized Tetrahymena CdMT rigorously documents the conclusion that modules are important units of CdMT evolution, which have undergone frequent and rapid gain/loss and shuffling. The transcriptional activity of the four newly identified genes was measured under different heavy metal exposure (Cd, Cu, Zn, Pb) using real-time quantitative PCR. The results showed that these genes were differentially induced after short (1 h) or long (24 h) metal exposure. The evolutionary diversity of Tetrahymena CdMTs is further discussed with regard to their induction by metal ions.

  • 193.
    Chen, Dong Lei
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Alavi, Yasaman
    Univ Melbourne, Sch BioSci, Australia.
    Brazeau, Martin D.
    Imperial Coll London, Dept Life Sci, Berks, England.
    Blom, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Millward, David
    British Geol Survey, Lyell Ctr, Edinburgh, Midlothian, Scotland.
    Ahlberg, Per E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    A partial lower jaw of a tetrapod from "Romer's Gap"2018In: Earth and environmental science transactions of the Royal Society of Edinburgh, ISSN 1755-6910, E-ISSN 1755-6929, Vol. 108, no 1, p. 55-65Article in journal (Refereed)
    Abstract [en]

    The first half of the Mississippian or Early Carboniferous (Tournaisian to mid-Visean), an interval of about 20 million years, has become known as "Romer's Gap" because of its poor tetrapod record. Recent discoveries emphasise the differences between pre-"Gap" Devonian tetrapods, unambiguous stem-group members retaining numerous "fish" characters indicative of an at least partially aquatic lifestyle, and post-"Gap" Carboniferous tetrapods, which are far more diverse and include fully terrestrial representatives of the main crown-group lineages. It seems that "Romer's Gap" coincided with the cladogenetic events leading to the origin of the tetrapod crown group. Here, we describe a partial right lower jaw ramus of a tetrapod from the late Tournaisian or early Visean of Scotland. The large and robust jaw displays a distinctive character combination, including a significant mesial lamina of the strongly sculptured angular, an open sulcus for the mandibular lateral line, a non-ossified narrow Meckelian exposure, a well-defined dorsal longitudinal denticle ridge on the prearticular, and a mesially open adductor fossa. A phylogenctic analysis places this specimen in a trichotomy with Crassigyrinus and baphetids + higher tetrapods in the upper part of the tetrapod stem group, above Whatcheeria, Pederpes, Ossinodus, Sigournea and Greererpeton. It represents a small but significant step in the gradual closure of "Romer's Gap".

  • 194.
    Chen, Dong Lei
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Blom, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Sanchez, Sophie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Tafforeau, Paul
    Estonian Marine Institute, University of Tartu.
    Märss, Tiiu
    Estonian Marine Institute, University of Tartu.
    Ahlberg, Per E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus 2017In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 4, no 5, article id 161084Article in journal (Refereed)
    Abstract [en]

    The numerous cushion-shaped tooth-bearing plates attributed to the stem-group osteichthyan Lophosteus superbus, which are argued here to represent the ancient form of inner dental arcade, display a unique and presumably primitive way of tooth shedding by basal hard tissue resorption. They carry regularly spaced, recumbent, gently recurved teeth arranged in transverse tooth files that diverge towards the lingual margin of the cushion. Three-dimensional (3D) reconstruction from propagation phase contrast synchrotron microtomography (PPC-SRμCT) reveals remnants of the first-generation teeth embedded in the basal plate that have never been discerned in any taxa. These teeth were shed by semi-basal resorption with the periphery of their bases retained as dentine rings. The rings are highly overlapped, which evidences tooth shedding prior to adding the next first-generation tooth. Later teeth at the same sites underwent cyclical replacing and shedding through basal resorption, producing stacks of buried resorption surfaces separated by bone of attachment. The number and spatial arrangement of resorption surfaces elucidates that basal resorption of replacement teeth had taken place at the older tooth sites before the addition of the youngest first-generation teeth at the lingual margin. Thus the replacement tooth buds cannot have been generated by a single permanent dental lamina, but must have arisen either from successional dental laminae associated with the predecessor teeth, or directly from the dental epithelium of these teeth. The virtual histological dissection of these Late Silurian microfossils broadens our understanding of the development of the gnathostome dental systems and the acquisition of the osteichthyan-type of tooth replacement. 

  • 195.
    Chen, Donglei
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Squamation in Andreolepis from the late Silurian of Sweden2010Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The origin of osteichthyans (bony fishes and tetrapods) dates back to the Late Silurian, but theearly evolution of osteichthyans is poorly understood. Andreolepis is one of the oldest knownosteichthyans, but exclusively documented by detached and fragmented dermal microremains.Nevertheless, Andreolepis has unequivocally been attributed to the osteichthyan stem group.A variety of isolated scales of Andreolepis from Gotland, Sweden provides a large dataset,which would potentially improve our understanding of the acquisition of the osteichthyanbody plan. In the present study, various forms of Andreolepis scales were classified into tenmorphotypes by landmark-based geometric morphometrics. Based on comparative anatomyand functional morphology, each morphotype was assigned to a specific area of the body anda squamation model of Andreolepis was established. In this model, scales are allocated toanterior-mid lateral flank scales, posterior lateral flank scales, caudal peduncle scales, pectoralpeduncle scales, dorsal flank scales, dorsal fulcral scales, caudal fulcral scales, ventral flankscales, medioventral scales and cranial scales.

  • 196.
    Chen, Donglei
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.