uu.seUppsala University Publications
Change search
Refine search result
1234567 101 - 150 of 1466
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101. Bergman, Ake
    et al.
    Andersson, Anna-Maria
    Becher, Georg
    van den Berg, Martin
    Blumberg, Bruce
    Bjerregaard, Poul
    Bornehag, Carl-Gustaf
    Bornman, Riana
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Brian, Jayne V.
    Casey, Stephanie C.
    Fowler, Paul A.
    Frouin, Heloise
    Giudice, Linda C.
    Iguchi, Taisen
    Hass, Ulla
    Jobling, Susan
    Juul, Anders
    Kidd, Karen A.
    Kortenkamp, Andreas
    Lind, Monica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Martin, Olwenn V.
    Muir, Derek
    Ochieng, Roseline
    Olea, Nicolas
    Norrgren, Leif
    Ropstad, Erik
    Ross, Peter S.
    Ruden, Christina
    Scheringer, Martin
    Skakkebaek, Niels Erik
    Soder, Olle
    Sonnenschein, Carlos
    Soto, Ana
    Swan, Shanna
    Toppari, Jorma
    Tyler, Charles R.
    Vandenberg, Laura N.
    Vinggaard, Anne Marie
    Wiberg, Karin
    Zoeller, R. Thomas
    Science and policy on endocrine disrupters must not be mixed: a reply to a "common sense" intervention by toxicology journal editors2013In: Environmental health, ISSN 1476-069X, E-ISSN 1476-069X, Vol. 12, p. 69-Article in journal (Other academic)
    Abstract [en]

    The "common sense" intervention by toxicology journal editors regarding proposed European Union endocrine disrupter regulations ignores scientific evidence and well-established principles of chemical risk assessment. In this commentary, endocrine disrupter experts express their concerns about a recently published, and is in our considered opinion inaccurate and factually incorrect, editorial that has appeared in several journals in toxicology. Some of the shortcomings of the editorial are discussed in detail. We call for a better founded scientific debate which may help to overcome a polarisation of views detrimental to reaching a consensus about scientific foundations for endocrine disrupter regulation in the EU.

  • 102. Bergman, Ake
    et al.
    Heindel, Jerrold J.
    Kasten, Tim
    Kidd, Karen A.
    Jobling, Susan
    Neira, Maria
    Zoeller, R. Thomas
    Becher, Georg
    Bjerregaard, Poul
    Bornman, Riana
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Kortenkamp, Andreas
    Muir, Derek
    Drisse, Marie-Noel Brune
    Ochieng, Roseline
    Skakkebaek, Niels E.
    Bylehn, Agneta Sunden
    Iguchi, Taisen
    Toppari, Jorma
    Woodruff, Tracey J.
    The Impact of Endocrine Disruption: A Consensus Statement on the State of the Science2013In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 121, no 4, p. A104-A106Article in journal (Other academic)
  • 103.
    Bergman, Åke
    et al.
    Swedish Toxicol Sci Res Ctr Swetox, Sodertalje, Sweden..
    Becher, Georg
    Norwegian Inst Publ Hlth, Oslo, Norway..
    Blumberg, Bruce
    Univ Calif Irvine, Irvine, CA USA..
    Bjerregaard, Poul
    Univ Southern Denmark, Odense, Denmark..
    Bornman, Riana
    Univ Pretoria, Sch Hlth Syst & Publ Hlth, ZA-0002 Pretoria, South Africa..
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Casey, Stephanie C.
    Univ Calif Irvine, Irvine, CA USA..
    Frouin, Heloise
    Vancouver Aquarium Marine Sci Ctr, Vancouver, BC, Canada..
    Giudice, Linda C.
    Univ Calif San Francisco, San Francisco, CA 94143 USA..
    Heindel, Jerrold J.
    Natl Inst Environm Hlth Sci, Res Triangle Pk, NC USA..
    Iguchi, Taisen
    Natl Inst Basic Biol, Okazaki, Aichi 444, Japan..
    Jobling, Susan
    Brunel Univ London, Uxbridge, Middx, England..
    Kidd, Karen A.
    Univ New Brunswick, New Brunswick, NJ USA..
    Kortenkamp, Andreas
    Brunel Univ London, Uxbridge, Middx, England..
    Lind, P. Monica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Muir, Derek
    Environm Canada, Burlington, ON L7R 4A6, Canada..
    Ochieng, Roseline
    Aga Khan Univ Hosp, Nairobi, Kenya..
    Ropstad, Erik
    Norwegian Univ Life Sci, Oslo, Norway..
    Ross, Peter S.
    Vancouver Aquarium Marine Sci Ctr, Vancouver, BC, Canada..
    Skakkebaek, Niels Erik
    Univ Copenhagen, Copenhagen Univ Hosp, Copenhagen, Denmark..
    Toppari, Jorma
    Univ Turku, Turku, Finland..
    Vandenberg, Laura N.
    Univ Massachusetts, Amherst, MA 01003 USA..
    Woodruff, Tracey J.
    Univ Calif San Francisco, San Francisco, CA 94143 USA..
    Zoeller, R. Thomas
    Univ Massachusetts, Amherst, MA 01003 USA..
    Manufacturing doubt about endocrine disrupter science - A rebuttal of industry-sponsored critical comments on the UNEP/WHO report "State of the Science of Endocrine Disrupting Chemicals 2012"2015In: Regulatory toxicology and pharmacology, ISSN 0273-2300, E-ISSN 1096-0295, Vol. 73, no 3, p. 1007-1017Article in journal (Other academic)
    Abstract [en]

    We present a detailed response to the critique of "State of the Science of Endocrine Disrupting Chemicals 2012" (UNEP/WHO, 2013) by financial stakeholders, authored by Lamb et al. (2014). Lamb et al.'s claim that UNEP/WHO (2013) does not provide a balanced perspective on endocrine disruption is based on incomplete and misleading quoting of the report through omission of qualifying statements and inaccurate description of study objectives, results and conclusions. Lamb et al. define extremely narrow standards for synthesizing evidence which are then used to dismiss the UNEP/WHO 2013 report as flawed. We show that Lamb et al. misuse conceptual frameworks for assessing causality, especially the Bradford Hill criteria, by ignoring the fundamental problems that exist with inferring causality from empirical observations. We conclude that Lamb et al.'s attempt of deconstructing the UNEP/WHO (2013) report is not particularly erudite and that their critique is not intended to be convincing to the scientific community, but to confuse the scientific data. Consequently, it promotes misinterpretation of the UNEP/WHO (2013) report by non-specialists, bureaucrats, politicians and other decision makers not intimately familiar with the topic of endocrine disruption and therefore susceptible to false generalizations of bias and subjectivity.

  • 104.
    Beznosov, Pavel A.
    et al.
    Russian Acad Sci, Ural Branch, Komi Sci Ctr, Inst Geol, Syktyvkar, Russia.
    Clack, Jennifer A.
    Univ Cambridge, Univ Museum Zool, Cambridge, England.
    Luksevics, Ervins
    Univ Latvia, Dept Geol, Riga, Latvia.
    Ruta, Marcello
    Univ Lincoln, Sch Life Sci, Joseph Banks Labs, Lincoln, England.
    Ahlberg, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Morphology of the earliest reconstructable tetrapod Parmastega aelidae2019In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 574, no 7779, p. 527-531Article in journal (Refereed)
    Abstract [en]

    The known diversity of tetrapods of the Devonian period has increased markedly in recent decades, but their fossil record consists mostly of tantalizing fragments(1-15). The framework for interpreting the morphology and palaeobiology of Devonian tetrapods is dominated by the near complete fossils of Ichthyostega and Acanthostega; the less complete, but partly reconstructable, Ventastega and Tulerpeton have supporting roles(2,4,16-34). All four of these genera date to the late Famennian age (about 365-359 million years ago)-they are 10 million years younger than the earliest known tetrapod fragments(5,10), and nearly 30 million years younger than the oldest known tetrapod footprints(35). Here we describe Parmastega aelidae gen. et sp. nov., a tetrapod from Russia dated to the earliest Famennian age (about 372 million years ago), represented by three-dimensional material that enables the reconstruction of the skull and shoulder girdle. The raised orbits, lateral line canals and weakly ossified postcranial skeleton of P. aelidae suggest a largely aquatic, surface-cruising animal. In Bayesian and parsimony-based phylogenetic analyses, the majority of trees place Parmastega as a sister group to all other tetrapods.

  • 105.
    Bharali, Pankaj
    et al.
    Rajiv Gandhi University, Arunachal Pradesh, India.
    Das, Arup Kumar
    Rajiv Gandhi University, Arunachal Pradesh, India.
    Lidén, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Notes on the alpine flora of Arunachal Pradesh: including several species new to India2019In: Plant diversity in the Himalaya hotspot region: volume to celebrate the completion of university service of Dr. Abhaya Prasad Das / [ed] A.P. Das; Subir Bera, Dehradun: Bishen Singh Mahendra Pal Singh , 2019, p. 163-194Chapter in book (Refereed)
  • 106.
    Bimpisidis, Zisis
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    König, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Stagkourakis, Stefanos
    Karolinska Inst, Dept Neurosci, S-17177 Stockholm, Sweden.
    Zell, Vivien
    Univ Calif San Diego, Dept Neurosci, La Jolla, CA 92093 USA.
    Vlcek, Bianca
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Dumas, Sylvie
    Oramacell, 8 Rue Gregoire Tours, F-75006 Paris, France.
    Giros, Bruno
    INSERM, UMRS 1130, F-75005 Paris, France;CNRS, Unite Mixte Rech 8246, F-75005 Paris, France;Univ Paris 06, Sorbonne Univ, Neurosci Paris Seine, F-75005 Paris, France;Douglas Mental Hlth Univ Inst, 6875 LaSalle Blvd, Verdun, PQ H4H 1R3, Canada;McGill Univ, Dept Psychiat, Montreal, PQ, Canada.
    Broberger, Christian
    Karolinska Inst, Dept Neurosci, S-17177 Stockholm, Sweden.
    Hnasko, Thomas S.
    Univ Calif San Diego, Dept Neurosci, La Jolla, CA 92093 USA;Res Serv VA San Diego Healthcare Syst, La Jolla, CA 92161 USA.
    Wallén-Mackenzie, Åsa
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    The NeuroD6 Subtype of VTA Neurons Contributes to Psychostimulant Sensitization and Behavioral Reinforcement2019In: eNeuro, E-ISSN 2373-2822, Vol. 6, no 3, article id e0066-19.2019Article in journal (Refereed)
    Abstract [en]

    Reward-related behavior is complex and its dysfunction correlated with neuropsychiatric illness. Dopamine (DA) neurons of the ventral tegmental area (VTA) have long been associated with different aspects of reward function, but it remains to be disentangled how distinct VTA DA neurons contribute to the full range of behaviors ascribed to the VTA. Here, a recently identified subtype of VTA neurons molecularly defined by NeuroD6 (NEX1M) was addressed. Among all VTA DA neurons, less than 15% were identified as positive for NeuroD6. In addition to dopaminergic markers, sparse NeuroD6 neurons expressed the vesicular glutamate transporter 2 (Vglut2) gene. To achieve manipulation of NeuroD6 VTA neurons, NeuroD6(NEX)-Cre-driven mouse genetics and optogenetics were implemented. First, expression of vesicular monoamine transporter 2 (VMAT2) was ablated to disrupt dopaminergic function in NeuroD6 VTA neurons. Comparing Vmat2(Cre)(lox/lox;NEX-) conditional knock-out (cKO) mice with littermate controls, it was evident that baseline locomotion, preference for sugar and ethanol, and place preference upon amphetamine-induced and cocaine-induced conditioning were similar between genotypes. However, locomotion upon repeated psychostimulant administration was significantly elevated above control levels in cKO mice. Second, optogenetic activation of NEX-Cre VTA neurons was shown to induce DA release and glutamatergic postsynaptic currents within the nucleus accumbens. Third, optogenetic stimulation of NEX-Cre VTA neurons in vivo induced significant place preference behavior, while stimulation of VTA neurons defined by Calretinin failed to cause a similar response. The results show that NeuroD6 VTA neurons exert distinct regulation over specific aspects of reward-related behavior, findings that contribute to the current understanding of VTA neurocircuitry.

  • 107.
    Bladin, Emelie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Effects of low-dose developmental exposure to Bisphenol A: Hepatic gene expression and hepatic lipid accumulation in juvenile Fischer 344 rats2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: The endocrine-disrupting chemical bisphenol A (BPA) is suggested to have a potential role in the development of obesity and metabolic disorders. Human exposure occurs worldwide and the developmental period seems to be particularly sensitive, even to very low doses. In January 2015 the European Food Safety Authority (EFSA) lowered the tolerable daily intake (TDI) from 50 μg/kg bw/day to 4 μg/kg bw/day. Ingestion of BPA-contaminated food is the main route of exposure and biotransformation occurs in the liver. Little is known about the effects of BPA exposure on basal metabolic rate and hepatic homeostasis.

    Objectives: This study aimed to investigate potential alterations on hepatic gene expression and hepatic lipid accumulation due to low-dose perinatal BPA developmental exposure.

    Methods: Pregnant Fischer 344 rats were exposed to a lower dose (0.5 μg/kg bw/day) and a higher dose (50 μg/kg bw/day) of BPA via their drinking water during gestation and lactation until weaning. The offspring were exposed in utero and during lactation. They were sacrificed at five weeks of age. Liver mRNA gene expression was measured using qPCR and potential lipid accumulation in the liver was examined using image analysis (ImageJ) of micrographs of tissue sections.

    Results: Perinatal exposure to BPA altered the mRNA expression in males. The mRNA levels of the pro adipogenic transcription factor CCAAT/enhancer binding protein, alpha (C/EBP-α), were 26% lower in higher-dose exposed males compared to controls (p=0.05). No significant effects on mRNA expression were seen in females. Liver lipid accumulation was not significantly altered by BPA exposure.

    Conclusion: Perinatal low-dose BPA exposure (0.5 and 50 μg/kg bw/day), altered hepatic expression of one gene involved in adipogenic transcription in the juvenile male offspring. The results support the potential role of low-dose BPA exposure on metabolic homeostasis and it might be of concern with regard to the currently allowed TDI and the ubiquitous exposure among humans

  • 108.
    Blazcjowski, Blazcj
    et al.
    Polish Acad Sci, Inst Paleobiol, Twarda 51-55, PL-00818 Warsaw, Poland..
    Niedzwiedzki, Grzegorz
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Boukhalfa, Kamel
    Univ Gabes, Fac Sci, City Riadh Zerig 6029, Gabes, Tunisia..
    Soussi, Mohamed
    Univ Tunis El Manar, Dept Geol, Fac Sci, Tunis 2092, Tunisia..
    Limulitella tejraensis, a new species of limulid (Chelicerata, Xiphosura) from the Middle Triassic of southern Tunisia (Saharan Platform)2017In: Journal of Paleontology, ISSN 0022-3360, E-ISSN 1937-2337, Vol. 91, no 5, p. 960-967Article in journal (Refereed)
    Abstract [en]

    Numerous well-preserved remains of a new limulid species from the Anisian-lower Ladinian (Middle Triassic) of the Tejra section of southern Tunisia are described. Comparisons are made with limulids from the Triassic deposits of Europe and Australia. The new specimens are congeneric with the type species of Limulitella, but show some morphological differences. Here we describe Limulitella tejraensis new species, a small limulid with semicircular prosoma, small and triangular opisthosoma, well-defined axial ridge, and pleurae along both ridges of the opisthosoma. The Tunisian Limulitella fossils are associated with conchostracans, bivalves, gastropods, and microconchids. Sedimentological and paleontological data from the Tejra section suggest freshwater to brackish-water conditions during the formation of the fossil-bearing interval and the influence of marine transgression into a playa-like environment. Supposed adaptation to the stressful environment sheds new light on the origin and survival of the extant limulines. This is the first report of limulid body fossils from the Triassic of North Africa and the first documentation of Limulitella in the Middle Triassic of northern Gondwanaland.

  • 109.
    Blieck, Alain
    et al.
    Université Lille – 1, France.
    Zigaite, Zivile
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Early and Middle Palaeozoic Vertebrate Palaeobiogeography: recent advances and critical comments2011In: Palaeozoic Early Vertebrates: II Obruchev Symposium. Abstracts / [ed] Oleg Lebedev and Alexander Ivanov, 2011, p. 28-28Conference paper (Other academic)
  • 110.
    Blieck, Alain
    et al.
    Université Lille – 1, France.
    Žigaitė, Živilė
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Paléobiogéographie des vertébrés du Paléozoïque inférieur et moyen: données et interprétations récentes2011In: Résumés des communications du congrès 2011 de l’Association Paléontologique Française / [ed] Bertrand Lefebre, 2011Conference paper (Other academic)
  • 111.
    Bloch, Natasha, I
    et al.
    UCL, Dept Genet Evolut & Environm, London, England.
    Corral-Lopez, Alberto
    Stockholm Univ, Dept Zool Ethol, Stockholm, Sweden.
    Buechel, Severine D.
    Stockholm Univ, Dept Zool Ethol, Stockholm, Sweden.
    Kotrschal, Alexander
    Stockholm Univ, Dept Zool Ethol, Stockholm, Sweden.
    Kolm, Niclas
    Stockholm Univ, Dept Zool Ethol, Stockholm, Sweden.
    Mank, Judith E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. UCL, Dept Genet Evolut & Environm, London, England.
    Early neurogenomic response associated with variation in guppy female mate preference2018In: Nature Ecology & Evolution, E-ISSN 2397-334X, Vol. 2, no 11, p. 1772-1781Article in journal (Refereed)
    Abstract [en]

    Understanding the evolution of mate choice requires dissecting the mechanisms of female preference, particularly how these differ among social contexts and preference phenotypes. Here, we studied the female neurogenomic response after only 10 min of mate exposure in both a sensory component (optic tectum) and a decision-making component (telencephalon) of the brain. By comparing the transcriptional response between females with and without preferences for colourful males, we identified unique neurogenomic elements associated with the female preference phenotype that are not present in females without preference. A network analysis revealed different properties for this response at the sensory-processing and the decision-making levels, and we show that this response is highly centralized in the telencephalon. Furthermore, we identified an additional set of genes that vary in expression across social contexts, beyond mate evaluation. We show that transcription factors among these loci are predicted to regulate the transcriptional response of the genes we found to be associated with female preference.

  • 112.
    Blom, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    New birkeniid anaspid from the Lower Devonian of Scotland and its phylogenetic implications2012In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 55, no 3, p. 641-652Article in journal (Refereed)
    Abstract [en]

    Abstract:  A new possible stem gnathostome, Kerreralepis carinata gen. et sp. nov., is described on the basis of a single specimen from the Lower Devonian of the island of Kerrera in the Inner Hebrides, Scotland. It is recognized as an anaspid by the chevron-like arranged rod-shaped scales on the trunk, gill openings extending behind the orbits in a slanting row and a series of median dorsal ridge scales. This specimen also has a series of median ventral plates, indicating the presence of a preanal fin-fold, which in turn has consequences for interpretations of other problematic stem gnathostomes and their phylogenetic context. A cladistic analysis supports a monophyletic Anaspida including the scale-covered birkeniids but excluding Lasanius as well as anaspid-like forms such as Euphanerops and Jamoytius. The establishment of a new genus and species increases the diversity of anaspids and allows for a more detailed study of anaspid interrelationships. An ingroup analysis using Lasanius as an outgroup resolves Birkenia as a rather basal anaspid, sister to all other anaspids, alternatively sister to a clade represented by the taxa from Ringerike, Norway, and the closely associated taxon from Saaremaa Island, Estonia. These topologies agree rather well with the present fossil record of anaspids.

  • 113.
    Blom, Henning
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Jerve, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Qu, Qin Ming
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Chen, Dong Lei
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Märss, Tiiu
    Tallinn University of Technology.
    Dupret, Vincent
    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.
    Ahlberg, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Affinities of Lophosteus and the origin of the osteichthyan body plan2011In: / [ed] Streng, Kear, 2011, p. 3-4Conference paper (Refereed)
  • 114.
    Blom, Henning
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Jerve, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Qu, Qingming
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Chen, Donglei
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Märss, Tiiu
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Dupret, Vincent
    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.
    Ahlberg, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    The affinity of Lophosteus and the evolution of osteichthyan characters2011Conference paper (Other academic)
  • 115.
    Blom, Henning
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Jerve, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Qu, Qinming
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Chen, Dong Lei
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Märss, Tiiu
    Tallinn University of Technology.
    Dupret, Vincent
    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.
    Ahlberg, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    The affinity of Lophosteus  and the evolution of osteichthyan characters2011Conference paper (Refereed)
  • 116.
    Blom, Henning
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Evolution and Developmental Biology.
    Märss, Tiiu
    The interrelationships and evolutionary history of anaspids2010In: Morphology, Phylogeny and Paleobiogeography of Fossil Fishes: Honoring Meemann Chang / [ed] David K. Elliott, John G. Maisey, Xiaobo Yu & Desui Miao, München: Dr. Friedrich Pfeil , 2010, p. 45-58Chapter in book (Other academic)
  • 117.
    Blom, Henning
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Zigaite, Zivile
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    New thelodont findings from the Lower Devonian Andrée Land Group, Spitsbergen, and their implications for biostratigraphy2012Conference paper (Other academic)
  • 118. Bogdanska, Jasna
    et al.
    Borg, Daniel
    Sundström, Maria
    Bergström, Ulrika
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Halldin, Krister
    Abedi-Valugerdi, Manuchehr
    Bergman, Åke
    Nelson, Buck
    DePierre, Joseph
    Nobel, Stefan
    Tissue distribution of S-35-labelled perfluorooctane sulfonate in adult mice after oral exposure to a low environmentally relevant dose or a high experimental dose2011In: Toxicology, ISSN 0300-483X, E-ISSN 1879-3185, Vol. 284, no 1-3, p. 54-62Article in journal (Refereed)
    Abstract [en]

    The widespread environmental pollutant perfluorooctane sulfonate (PFOS), detected in most animal species including the general human population, exerts several effects on experimental animals, e.g., hepatotoxicity, immunotoxicity and developmental toxicity. However, detailed information on the tissue distribution of PFOS in mammals is scarce and, in particular, the lack of available information regarding environmentally relevant exposure levels limits our understanding of how mammals (including humans) may be affected. Accordingly, we characterized the tissue distribution of this compound in mice, an important experimental animal for studying PFOS toxicity. Following dietary exposure of adult male C57/BL6 mice for 1-5 days to an environmentally relevant (0.031 mg/kg/day) or a 750-fold higher experimentally relevant dose (23 mg/kg/day) of S-35-PFOS, most of the radioactivity administered was recovered in liver, bone (bone marrow), blood, skin and muscle, with the highest levels detected in liver, lung, blood, kidney and bone (bone marrow). Following high daily dose exposure, PFOS exhibited a different distribution profile than with low daily dose exposure, which indicated a shift in distribution from the blood to the tissues with increasing dose. Both scintillation counting (with correction for the blood present in the tissues) and whole-body autoradiography revealed the presence of PFOS in all 19 tissues examined, with identification of thymus as a novel site for localization for PFOS and bone (bone marrow), skin and muscle as significant body compartments for PFOS. These findings demonstrate that PFOS leaves the bloodstream and enters most tissues in a dose-dependent manner.

  • 119. Bogdanska, Jasna
    et al.
    Sundstrom, Maria
    Bergström, Ulrika
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Borg, Daniel
    Abedi-Valugerdi, Manuchehr
    Bergman, Ake
    DePierre, Joseph
    Nobel, Stefan
    Tissue distribution of S-35-labelled perfluorobutanesulfonic acid in adult mice following dietary exposure for 1-5 days2014In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 98, p. 28-36Article in journal (Refereed)
    Abstract [en]

    Perfluorobutanesulfonyl fluoride (PBSF) has been introduced as a replacement for its eight-carbon homolog perfluorooctanesulfonyl fluoride (POSF) in the manufacturing of fluorochemicals. Fluorochemicals derived from PBSF may give rise to perfluorobutanesulfonic acid (PFBS) as a terminal degradation product. Although basic mammalian toxicokinetic data exist for PFBS, information on its tissue distribution has only been reported in one study focused on rat liver. Therefore, here we characterized the tissue distribution of PFBS in mice in the same manner as we earlier examined its eight-carbon homolog perfluorooctanesulfonate (PFOS) to allow direct comparisons. Following dietary exposure of adult male C57/BL6 mice for 1,3 or 5 d to 16 mg S-35-PFBS kg(-1) d(-1), both scintillation counting and whole-body autoradiography (WBA) revealed the presence of PFBS in all of the 20 different tissues examined, demonstrating its ability to leave the bloodstream and enter tissues. After 5 d of treatment the highest levels were detected in liver, gastrointestinal tract, blood, kidney, cartilage, whole bone, lungs and thyroid gland. WBA revealed relatively high levels of PFBS in male genital organs as well, with the exception of the testis. The tissue levels increased from 1 to 3 d of exposure but appeared thereafter to level-off in most cases. The estimated major body compartments were whole bone, liver, blood, skin and muscle. This exposure to PFBS resulted in 5-40-fold lower tissue levels than did similar exposure to PFOS, as well as in a different pattern of tissue distribution, including lower levels in liver and lungs relative to blood.

  • 120.
    Borg, Daniel
    et al.
    Karolinska Institutet.
    Bogdanska, Jasna
    Stockholms Universitet.
    Sundström, Maria
    Stockholms Universitet.
    Nobel, Stefan
    Stockholms Universitet.
    Håkansson, Helen
    Karolinska Institutet.
    Bergman, Åke
    Stockholms Universitet.
    Depierre, Jospeh W
    Stockholms Universitet.
    Halldin, Krister
    Karolinska Institutet.
    Bergström, Ulrika
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Tissue distribution of (35)S-labelled perfluorooctane sulfonate (PFOS) in C57Bl/6 mice following late gestational exposure2010In: Reproductive Toxicology, ISSN 0890-6238, E-ISSN 1873-1708, Vol. 30, no 4, p. 558-565Article in journal (Refereed)
    Abstract [en]

    Exposure of rodents in utero to perfluorooctane sulfonate (PFOS) impairs perinatal development and survival. Following intravenous or gavage exposure of C57Bl/6 mouse dams on gestational day (GD) 16 to (35)S-PFOS (12.5mg/kg), we determined the distribution in dams, fetuses (GD18 and GD20) and pups (postnatal day 1, PND1) employing whole-body autoradiography and liquid scintillation counting. In dams, levels were highest in liver and lungs. After placental transfer, (35)S-PFOS was present on GD18 at 2-3 times higher levels in lungs, liver and kidneys than in maternal blood. In PND1 pups, levels in lungs were significantly higher than in GD18 fetuses. A heterogeneous distribution of (35)S-PFOS was observed in brains of fetuses and pups, with levels higher than in maternal brain. This first demonstration of substantial localization of PFOS to both perinatal and adult lungs is consistent with evidence describing the lung as a target for the toxicity of PFOS at these ages.

  • 121. Botting, Joseph P.
    et al.
    Cardenas, Paco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Peel, John S.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    A Crown-Group Demosponge from the Early Cambrian Sirius Passet Biota, North Greenland2015In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 58, no 1, p. 35-43Article in journal (Refereed)
    Abstract [en]

    Calibration of the divergence times of sponge lineages and understanding of their phylogenetic history are hampered by the difficulty in recognizing crown versus stem groups in the fossil record. A new specimen from the lower Cambrian (Series 2, Stage 3; approximately 515Ma) Sirius Passet Biota of North Greenland has yielded a diagnostic spicule assemblage of the extant demosponge lineages Haploscleromorpha and/or Heteroscleromorpha. The specimen has disarticulated approximately in situ, but represents an individual sponge that possessed monaxon spicules combined with a range of slightly smaller sigma, toxa and unique spiral morphologies. The combination of spicule forms, together with their relatively large size, suggests that the sponge represents the stem lineage of Haploscleromorpha+Heteroscleromorpha. This is the first crown-group demosponge described from the early Cambrian and provides the most reliable calibration point currently available for phylogenetic studies.

  • 122.
    Brandt, Ingvar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Laboratory vs Field Studies to Assess Environmental Hazards and Risks Posed by Pharmaceuticals for Human Use2010In: Towards Sustainable Pharmaceuticals in a Healthy Society: MistraPharma Research / [ed] Christina Rudén, Karin Liljelund, Helene Hagerman, MistraPharma , 2010, p. 72-79Chapter in book (Other academic)
  • 123.
    Bremer, Oskar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Distribution of Silurian vertebrates on Gotland, Sweden2016Conference paper (Other academic)
  • 124.
    Bremer, Oskar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Geology, stratigraphy, and fossil vertebrates of Gotland, Sweden: a review2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Silurian limestones of Gotland, Sweden, and their exceptionally well-preserved fossils have attracted the interest of scientists for more than 200 years. The sedimentary rocks represent approximately 10 million years of time, and were deposited in a shallow, equatorial inland sea named the Baltic Basin. The majority of the sediments are composed of reef-associated strata, but a general transition can be seen along the strike from shallow water in the northeast to deeper shelf environments in the southwest. The understanding of the stratigraphy and the geology of Gotland has greatly improved during the last decades. This research on Gotland has also led to the discovery of a series of stable isotope excursions and extinctions among several faunal groups. These events were probably linked to cycles in atmospheric and oceanic states, and three of them have been recognized globally. The Baltic Basin was also home to a variety of early vertebrates. The first fossil vertebrates from Gotland were reported in 1861, but the most extensive study of these early fishes was performed in the late 1900s. More recently it was shown that the vertebrates were also affected by one of the extinction events. This thesis is an extensive review of previous work and will form a geological basis for future studies. In this work, all previous reports of vertebrates have been gathered, reviewed, and the old samples have been placed in an updated stratigraphical framework. The scale taxonomy of Gotland vertebrates, including the Baltic acanthodians, has been evaluated and partly revised. Additionally, the depositional environments of the sampled areas have been investigated. Studying the vertebrates of Gotland is important for understanding the distribution of vertebrates through time and in different environments during the Silurian. Initial results indicate environmental preferences among vertebrates on both group and species-level, which may prove useful for testing the vertebrate biozonation developed for the Silurian.

    List of papers
    1. An updated stratigraphic and environmental framework for the distribution of Silurian vertebrates on Gotland
    Open this publication in new window or tab >>An updated stratigraphic and environmental framework for the distribution of Silurian vertebrates on Gotland
    2015 (English)In: Estonian journal of earth sciences, ISSN 1736-4728, E-ISSN 1736-7557, Vol. 64, no 1, p. 13-18Article in journal (Refereed) Published
    Keywords
    vertebrate distribution, stratigraphy, facies, Silurian events, Gotland, Sweden
    National Category
    Developmental Biology Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-251824 (URN)10.3176/earth.2015.03 (DOI)000351327700004 ()
    Available from: 2015-04-27 Created: 2015-04-24 Last updated: 2017-08-21
    2. Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland
    Open this publication in new window or tab >>Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland
    Show others...
    2018 (English)In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 155, no 7, p. 1523-1541Article in journal (Refereed) Published
    Abstract [en]

    Vertebrate microremains from the upper Silurian Winnica Formation in the Holy Cross Mountains, Poland are described from the Winnica and Rzepin sections. Both sites record the uppermost part of the Supianka Member, but represent different depositional environments. The Winnica samples come from a low-energy environment, while the Rzepin sample was taken from a high-energy, oolitic facies. Both sites contain thelodonts Thelodus parvidens, Thelodus trilobatus, an anaspid cf. Liivilepis and a number of acanthodian scales of 'nostolepid', poracanthodid and 'gomphonchid' types. Notable differences between the sites are the addition of the osteostracan Tahulaspis cf. ordinata, the thelodont Paralogania ludlowiensis and acanthodian scales identified as Nostolepis gracilis in the Rzepin section. Placing the vertebrate faunas within the vertebrate biozonation established for the Silurian proved difficult. The suggested late Ludlow age for the Supianka Member based on sequence stratigraphical and chemostratigraphical correlations cannot be definitely confirmed or refuted, but a late Ludfordian age seems the most plausible based on invertebrate and vertebrate faunas. The much lower abundance of poracanthodid acanthodians in the Rzepin sample supports the notion of Poracanthodes porosus Zone as a deep-water equivalent to a number of vertebrate biozones. The presence of P. ludlowiensis only in the oolitic sample confirms a long temporal range, but restricted environmental distribution for this taxon.

    National Category
    Other Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-281657 (URN)10.1017/S0016756817000681 (DOI)000443814900008 ()
    Available from: 2016-03-29 Created: 2016-03-29 Last updated: 2018-11-06Bibliographically approved
  • 125.
    Bremer, Oskar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Silurian vertebrates of Gotland (Sweden) and the Baltic Basin2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    During the Silurian, the Swedish island Gotland was positioned close to the equator and covered by a shallow sea called the Baltic Basin. The sedimentary rocks (predominantly carbonates) comprising most of the island today were initially formed in this warm sea, and the relatively complete succession of rocks often contains fossil fragments and scales from early vertebrates, including heterostracans, anaspids, thelodonts, osteostracans, acanthodians, and a stem-osteichthyan. Fossils of early vertebrates become increasingly more common in younger Silurian rocks, but are mostly represented by fragmentary remains and rarer occurrences of articulated jawless vertebrates (agnathans). However, the record of articulated specimens and jawed vertebrates (gnathostomes) are more numerous in rocks of the following Devonian Period. Isolated peaks of agnathan diversity during the Silurian and disarticulated remains of gnathostomes from this period hint at a cryptic evolutionary history. A micropaleontological approach with broader sampling may provide a better understanding of early vertebrate distribution patterns and hopefully give some insights into this history. The objective of this study was to build upon previous sampling on Gotland and to use established frameworks for disarticulated remains with the aim of making comparisons with similar studies performed in the East Baltic. However, difficulties locating the collections from these previous works necessitated a different focus. Undescribed museum collections and newly sampled material enabled some taxonomical revisions and greatly improved the understanding of vertebrate distribution in the youngest part of the Gotland sequence. It also indicated that this interval may represent the early stages of the diversification of gnathostomes that become increasingly dominant toward the end of the Silurian. Furthermore, the description of samples from partly coeval sections in Poland enabled some preliminary comparisons outside of Gotland, and presented a striking example of restricted environmental occurrences for a thelodont taxon. This is encouraging for future sampling and investigations on Gotland. Together with the establishment of a facies-framework comparable to that developed in the East Baltic and correlations to other areas, this may prove fruitful for an increased understanding of early vertebrate distribution and evolution during the Silurian.

    List of papers
    1. An updated stratigraphic and environmental framework for the distribution of Silurian vertebrates on Gotland
    Open this publication in new window or tab >>An updated stratigraphic and environmental framework for the distribution of Silurian vertebrates on Gotland
    2015 (English)In: Estonian journal of earth sciences, ISSN 1736-4728, E-ISSN 1736-7557, Vol. 64, no 1, p. 13-18Article in journal (Refereed) Published
    Keywords
    vertebrate distribution, stratigraphy, facies, Silurian events, Gotland, Sweden
    National Category
    Developmental Biology Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-251824 (URN)10.3176/earth.2015.03 (DOI)000351327700004 ()
    Available from: 2015-04-27 Created: 2015-04-24 Last updated: 2017-08-21
    2. End-Wenlock terminal Mulde carbon isotope excursion in Gotland, Sweden: Integration of stratigraphy and taphonomy for correlations across restricted facies and specialized faunas
    Open this publication in new window or tab >>End-Wenlock terminal Mulde carbon isotope excursion in Gotland, Sweden: Integration of stratigraphy and taphonomy for correlations across restricted facies and specialized faunas
    Show others...
    2016 (English)In: Palaeogeography, Palaeoclimatology, Palaeoecology, ISSN 0031-0182, E-ISSN 1872-616X, Vol. 457, p. 304-322Article in journal (Refereed) Published
    National Category
    Earth and Related Environmental Sciences
    Research subject
    Earth Science with specialization in Historical Geology and Palaeontology
    Identifiers
    urn:nbn:se:uu:diva-299498 (URN)10.1016/j.palaeo.2016.06.031 (DOI)000380598800025 ()
    Available from: 2016-07-21 Created: 2016-07-21 Last updated: 2017-08-21
    3. Vertebrate remains and conodont biostratigraphy in the Ludlow Burgsvik Formation of Gotland, Sweden
    Open this publication in new window or tab >>Vertebrate remains and conodont biostratigraphy in the Ludlow Burgsvik Formation of Gotland, Sweden
    (English)Manuscript (preprint) (Other academic)
    National Category
    Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-328226 (URN)
    Available from: 2017-08-20 Created: 2017-08-20 Last updated: 2017-08-25
    4. Vertebrate dermal remains and conodont distribution in the upper Silurian Hamra and Sundre formations of Gotland, Sweden
    Open this publication in new window or tab >>Vertebrate dermal remains and conodont distribution in the upper Silurian Hamra and Sundre formations of Gotland, Sweden
    (English)Manuscript (preprint) (Other academic)
    National Category
    Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-328227 (URN)
    Available from: 2017-08-20 Created: 2017-08-20 Last updated: 2017-08-21
    5. Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland
    Open this publication in new window or tab >>Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland
    Show others...
    2018 (English)In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 155, no 7, p. 1523-1541Article in journal (Refereed) Published
    Abstract [en]

    Vertebrate microremains from the upper Silurian Winnica Formation in the Holy Cross Mountains, Poland are described from the Winnica and Rzepin sections. Both sites record the uppermost part of the Supianka Member, but represent different depositional environments. The Winnica samples come from a low-energy environment, while the Rzepin sample was taken from a high-energy, oolitic facies. Both sites contain thelodonts Thelodus parvidens, Thelodus trilobatus, an anaspid cf. Liivilepis and a number of acanthodian scales of 'nostolepid', poracanthodid and 'gomphonchid' types. Notable differences between the sites are the addition of the osteostracan Tahulaspis cf. ordinata, the thelodont Paralogania ludlowiensis and acanthodian scales identified as Nostolepis gracilis in the Rzepin section. Placing the vertebrate faunas within the vertebrate biozonation established for the Silurian proved difficult. The suggested late Ludlow age for the Supianka Member based on sequence stratigraphical and chemostratigraphical correlations cannot be definitely confirmed or refuted, but a late Ludfordian age seems the most plausible based on invertebrate and vertebrate faunas. The much lower abundance of poracanthodid acanthodians in the Rzepin sample supports the notion of Poracanthodes porosus Zone as a deep-water equivalent to a number of vertebrate biozones. The presence of P. ludlowiensis only in the oolitic sample confirms a long temporal range, but restricted environmental distribution for this taxon.

    National Category
    Other Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-281657 (URN)10.1017/S0016756817000681 (DOI)000443814900008 ()
    Available from: 2016-03-29 Created: 2016-03-29 Last updated: 2018-11-06Bibliographically approved
  • 126.
    Bremer, Oskar
    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.
    An updated stratigraphic and environmental framework for the distribution of Silurian vertebrates on Gotland2015In: Estonian journal of earth sciences, ISSN 1736-4728, E-ISSN 1736-7557, Vol. 64, no 1, p. 13-18Article in journal (Refereed)
  • 127.
    Bremer, Oskar
    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.
    Biostratigraphy of early vertebrates on Gotland2014In: 4th Annual Meeting of IGCP 591, Estonia, 10 - 19 June 2014.: Abstracts and Field Guide / [ed] Heikki Bauert, Olle Hints, Tõnu Meidla & Peep Männik, Tartu: University of Tartu, 2014, p. 21-21Conference paper (Other academic)
  • 128.
    Bremer, Oskar
    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.
    Biostratigraphy of Silurian vertebrates from Gotland, Sweden, revisited: understanding spatial and temporal distributions2015In: Abstract volume of the 13th International symposium on Early and Lower Vertebrates / [ed] Kate Trinajstic, Zerina Johanson, Martha Richter and Catherine Boisvert, 2015Conference paper (Other academic)
  • 129.
    Bremer, Oskar
    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.
    Three-dimensional virtual histology of the osteostracan Dartmuthia revealed by synchrotron radiation microtomography2018Conference paper (Other academic)
  • 130.
    Bremer, Oskar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Jarochowska, Emilia
    Märss, Tiiu
    Vertebrate dermal remains and conodont distribution in the upper Silurian Hamra and Sundre formations of Gotland, SwedenManuscript (preprint) (Other academic)
  • 131.
    Bremer, Oskar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Jarochowska, Emilia
    Märss, Tiiu
    Blom, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Vertebrate remains and conodont biostratigraphy in the Ludlow Burgsvik Formation of Gotland, SwedenManuscript (preprint) (Other academic)
  • 132.
    Bremer, Oskar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Kear, Benjamin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Reassessment of the ‘last’ goniopholidid: denazinosuchus kirtlandicus from the late cretaceous of New Mexico2013In: Program and Abstract Book, 2013, p. 93-94Conference paper (Other academic)
  • 133.
    Bremer, Oskar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Niedzwiedzki, Grzegorz
    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.
    Dec, Marek
    Polish Acad Sci, Inst Paleobiol, Twarda 51-55, PL-00818 Warsaw, Poland.
    Kozłowski, Wojciech
    Univ Warsaw, Inst Geol, Zwirki & Wigury 93, PL-02089 Warsaw, Poland.
    Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland2018In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 155, no 7, p. 1523-1541Article in journal (Refereed)
    Abstract [en]

    Vertebrate microremains from the upper Silurian Winnica Formation in the Holy Cross Mountains, Poland are described from the Winnica and Rzepin sections. Both sites record the uppermost part of the Supianka Member, but represent different depositional environments. The Winnica samples come from a low-energy environment, while the Rzepin sample was taken from a high-energy, oolitic facies. Both sites contain thelodonts Thelodus parvidens, Thelodus trilobatus, an anaspid cf. Liivilepis and a number of acanthodian scales of 'nostolepid', poracanthodid and 'gomphonchid' types. Notable differences between the sites are the addition of the osteostracan Tahulaspis cf. ordinata, the thelodont Paralogania ludlowiensis and acanthodian scales identified as Nostolepis gracilis in the Rzepin section. Placing the vertebrate faunas within the vertebrate biozonation established for the Silurian proved difficult. The suggested late Ludlow age for the Supianka Member based on sequence stratigraphical and chemostratigraphical correlations cannot be definitely confirmed or refuted, but a late Ludfordian age seems the most plausible based on invertebrate and vertebrate faunas. The much lower abundance of poracanthodid acanthodians in the Rzepin sample supports the notion of Poracanthodes porosus Zone as a deep-water equivalent to a number of vertebrate biozones. The presence of P. ludlowiensis only in the oolitic sample confirms a long temporal range, but restricted environmental distribution for this taxon.

  • 134.
    Bremer, Oskar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Niedźwiedzki, Grzegorz
    Blom, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Dec, Marek
    Kozłowski, Wojciech
    Vertebrate microremains from the upper Silurian Winnica Formation of the Holy Cross Mountains, Poland2017Conference paper (Other academic)
  • 135.
    Brindefalk, Björn
    et al.
    Uppsala University, Science for Life Laboratory, SciLifeLab.
    Ettema, Thijs J. G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Viklund, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Thollesson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Andersson, Siv G. E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    A Phylometagenomic Exploration of Oceanic Alphaproteobacteria Reveals Mitochondrial Relatives Unrelated to the SAR11 Clade2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 9, p. e24457-Article in journal (Refereed)
    Abstract [en]

    Background: According to the endosymbiont hypothesis, the mitochondrial system for aerobic respiration was derived from an ancestral Alphaproteobacterium. Phylogenetic studies indicate that the mitochondrial ancestor is most closely related to the Rickettsiales. Recently, it was suggested that Candidatus Pelagibacter ubique, a member of the SAR11 clade that is highly abundant in the oceans, is a sister taxon to the mitochondrial-Rickettsiales clade. The availability of ocean metagenome data substantially increases the sampling of Alphaproteobacteria inhabiting the oxygen-containing waters of the oceans that likely resemble the originating environment of mitochondria.

    Methodology/Principal Findings: We present a phylogenetic study of the origin of mitochondria that incorporates metagenome data from the Global Ocean Sampling (GOS) expedition. We identify mitochondrially related sequences in the GOS dataset that represent a rare group of Alphaproteobacteria, designated OMAC (Oceanic Mitochondria Affiliated Clade) as the closest free-living relatives to mitochondria in the oceans. In addition, our analyses reject the hypothesis that the mitochondrial system for aerobic respiration is affiliated with that of the SAR11 clade.

    Conclusions/Significance: Our results allude to the existence of an alphaproteobacterial clade in the oxygen-rich surface waters of the oceans that represents the closest free-living relative to mitochondria identified thus far. In addition, our findings underscore the importance of expanding the taxonomic diversity in phylogenetic analyses beyond that represented by cultivated bacteria to study the origin of mitochondria.

  • 136.
    Brittebo, Eva
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Andersson, Helén
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Rönn, Monika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lind, Monica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lind, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cardiovascular epidemiology.
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Bioactivation and effects of environmental pollutants in human and rodent blood vessel endothelial cells2012In: Organohalogen compound database (http://www.dioxin20xx.org/ohc_database_search.htm), 2012Conference paper (Refereed)
    Abstract [en]

    Introduction

    Recent epidemiological studies reveal associations between exposure to environmental pollutants and cardiovascular disorders in humans. Elevated serum concentrations of polychlorinated biphenyls (PCBs) have for instance been associated with cardiovascular risk factors such as hypertension (1-3). Exposure to the carbonate plastic monomer bisphenol A (BPA) has been associated with an increased incidence of cardiovascular disease and atherogenic changes in the vascular wall (4-6). The contention that the human cardiovascular system is a sensitive target for toxic chemicals gain support from our earlier and recent experimental studies in rodents, birds and fish, as well as in cultured human primary endothelial cells. It is also compatible with earlier observations that certain polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogens that may also contribute to atherosclerosis in mice and birds (7,8).

    In this presentation we will briefly discuss effects of Ah receptor (AhR) agonists (e.g. the coplanar PCB126 or BNF, ß-naphthoflavone) on the expression of cytochrome P450 (CYP)1 enzymes in various endothelia in rodents in vivo or ex vivo, as well as in cultured human umbilical vein endothelial cells (HUVEC). The CYP1-dependent bioactivation and irreversible binding of prototype polyaromatic hydrocarbons (PAH) and heterocyclic amines such as benzo(a)pyrene (BaP), 7,12-dimethyl- benz(a)anthracene (DMBA) and 3-amino-1,4-dimethyl-5H-pyrido- [4,3-b]indole (Trp-P1) in these endothelia will be reviewed. We will also report how PCB126 affects vasoactive factors in HUVEC, and how these effects are modulated by physiological 17ß-oestradiol concentrations. Some effects of PCB126, 1-nitropyrene (1-NP) and bisphenol A (BPA) on biomarkers for endothelial dysfunction, cell stress and DNA damage in HUVEC will finally be presented.

    Material and methods

    Human umbilical vein endothelial cells (HUVEC) were purchased from Science Cell Research laboratories, Carlsbad, CA. C57Bl mice and Wistar or Sprague Dawley rats were purchased from various suppliers. All animal experiments were approved by the Local Ethical Committee for Research on Animals in Uppsala and the studies followed the guidelines laid down by the Swedish and European Union legislation on animal experimentation. Rodents, tissue-slices and cultured cells were treated with model chemicals as previously described. Tape section and light microscopy autoradiographic imaging using 3H-labelled BaP, DMBA and Trp-P-1 and immunohistochemistry was performed as previously described (9-19). Precision-cut tissue slices for in vitro autoradiography were prepared as described in (14) and the slices were incubated with various 3H-labelled chemicals. HUVEC were exposed to various compounds and the detection of biomarkers of endothelial dysfunction, DNA damage were performed as described (20-22). Finally, female Fischer rats were exposed to BPA (0.025, 0.25 and 2.5 mg/l) and fructose (50 g/l) in the drinking water from 5 to 15 weeks of age to mimic human exposure (unpublished data).

    Results and discussion

    Co-localization of CYP1A1 expression and BaP, DMBA and Trp-P-1 adduct formation in endothelial linings As demonstrated by immunohistochemistry, a high CYP1A immunoreactivity occurred in capillaries of the heart, skeletal muscle, uterus and in blood-brain interfaces such as the leptomeninges and plexus choroideus, whereas no expression was observed for instance in cerebral capillary endothelial cells of mice treated with AhR agonists (9-11). No, or very low constitutive immunoreactivities were observed in these endothelia in vehicle-treated animals. No basal or induced CYP1B1 expression was observed in endothelial cells, while a weak CYP1B1 immunostaining was detected in the muscle layer of small arteries. It should be noted that in subcellular preparations of whole organs, e.g. heart and brain, the CYP1A1 in endothelial cells is diluted due to cells that do not express high levels of CYP1A1, for examples myocytes or neurons, in excess. A cell-specific metabolism in endothelial cells may therefore remain undetected due to the presence of metabolically inactive cells. In order to detect minor sites of bioactivation such as endothelial linings we employed light microscopic autoradiographic imaging to examine the bioactivation and subsequent irreversible binding of the radiolabelled prototype toxicants in tissues of animals pretreated with AhR-agonists. As determined by light microscopic autoradiography of AhR-agonist-treated mice exposed to 3H-labelled BaP, DMBA or Trp-P-1 and birds exposed to 3H-Trp-P-1 a significant accumulation of non-extractable radioactivity occurred in endothelial linings (9-18). The bound radioactivity occurred in the nuclei and the perinuclear cytoplasm, suggesting that the autoradiograms depict both DNA- and protein-bound adducts. Since the binding sites of 3H-labelled BaP, DMBA or Trp-P-1 corresponded with the sites of CYP1A1 induction, we concluded that rodents express a constitutively low but highly inducible and functional CYP1A1 in endothelial cells. The binding of reactive metabolites in endothelial cells exceeded the binding in all other cell types in AhR-agonist treated mice and was abolished by pretreatment with the CYP1A1 inhibitor ellipticine, supporting a CYP1A1-catalysed metabolic activation in situ to a reactive species (9, 10,12). These findings imply that there is a preferential CYP1A1-catalysed formation of reactive metabolites from all three carcinogens in endothelial cells expressing high CYP1A1 levels. Interestingly, however, carcinogenesis in endothelial cells is a relative rare finding, suggesting that degenerative lesions and cell death may be more prevalent responses to metabolism-activated carcinogens/mutagens in these cells. Experiments with 3H-DMBA and 3H-Trp-P-1 in HUVEC confirmed that AhR-agonists induced an increased bioactivation, suggesting that also human endothelial cells should be targets for toxicity of reactive intermediates formed from CYP1A1- activated carcinogens/mutagens (17-18). This conclusion is supported by immunohistochemical studies on the heavily vascularized human endometrium demonstrating an expression of CYP1A1 and CYP1B1 protein in and around human endometrial blood vessels, although a large interindividual

    variation was observed (19). None of the endometrial biopsy samples displayed vascular expression of CYP2A6, CYP2B6, CYP2C8/2C9/2C19, CYP2D6, or CYP3A4/5 protein.

    Effects of PCB 126, 1-NP, and BPA on biomarkers of endothelial dysfunction and cell stress in endothelial cells In vitro studies demonstrated that PCB126 increased the levels of vasoconstriction factors and decreased the levels of vasodilating factors in cultured HUVEC in a fashion that is characteristic for endothelial dysfunction related to human hypertension. The study showed that the co-planar PCB126 induced expression of the endothelium-derived vasoconstriction factor COX-2 and stimulated formation of the vasoconstrictor prostaglandin PGF2 via the AhR in HUVEC (20). COX-2 is known to play a role in hypertension by catalysing the formation of vasoconstriction prostaglandins and by stimulating reactive oxygen species (ROS) production. Further studies demonstrated that PCB126 increased the production of the vasoconstriction prostaglandin PGF2 and ROS in HUVEC. The relationship between increased ROS production and human hypertension is well established, ROS promotes vasoconstriction by stimulating the production of vasoconstriction prostaglandins and by reducing bioavailability of the vasorelaxing factor NO. Indeed, exposure to PCB126 slightly reduced the production of NO in HUVEC. Furthermore, the PCB126-induced mRNA expressions of CYP1A1, CYP1B1 and COX-2 in HUVEC were enhanced in the presence of physiological levels of 17- estradiol. This suggests that increased levels of oestrogen stimulate AhR-dependent transcription of genes previously associated with endothelial dysfunction and hypertension.

    In another study we have examined the effects of a nitrated PAH, 1-nitropyrene, that is abundant in diesel exhausts (21). The results revealed that 1-NP induced DNA damage, increased levels of ROS and increased protein expression of the endoplasmic reticulum stress chaperone GRP78 in cultured HUVEC. Induction of CYP1A1 by PCB126 as well as inhibition of nitroreductive metabolism by dicoumarol attenuated the induction of DNA damage, intracellular ROS levels and GRP78 expression. This suggests that the effects of 1-NP on HUVEC were mediated by metabolites mainly formed at nitroreduction and not by CYP1-dependent bioactivation to reactive intermediates.

    Recent in vitro studies demonstrated that bisphenol A increased the mRNA expression of genes that regulate vasoconstriction and angiogenesis in HUVEC (eNOS, VEGF, VEGFR2, connexin 43 and ACE1) and in human cardiomyocytes (eNOS and ACE1) (22). The results also showed that BPA increased the expression of P-eNOS(ser1177) and the production of NO in HUVEC. NO is the main effector molecule in angiogenesis downstream of VEGF. Based on the findings that BPA increase the expression of proangiogenic factors we investigated whether BPA could stimulate in vitro angiogenesis in HUVEC using the endothelial tube formation assay. The results demonstrated that BPA increased HUVEC tube formation suggesting that BPA can act directly on the endothelium and stimulate angiogenesis. Long-term exposure in rats revealed that environmentally relevant levels of BPA, increased the cardiac mRNA expression of genes that regulate vasoconstriction and angiogenesis. Ten weeks exposure of rats from preadolescence to adulthood to BPA in the drinking water increased the

    expression of eNOS, VEGF, VEGFR2 and ACE1 in the heart. Taken together, the genes that were upregulated in rat cardiac tissues in vivo were also upregulated in human endothelial cells and cardiomyocytes in vitro. The heart is a heavily vascularized tissue that consists mainly of cardiac endothelial cells and cardiomyocytes and although cardiomyocytes dominate the volume of the myocardium the number of endothelial cells exceeds the number of cardiomyocytes by approximately three to one. Thus, the effects of BPA on eNOS VEGF, VEGFR2 and ACE1 mRNA expression in rat cardiac tissues are most likely to be related to an effect of BPA on endothelial cells but may also involve cardiomyocytes.

    We conclude that endothelial cells may be targets for bioactivation and toxicity of environmental pollutants. The immunohistochemical and autoradiographic data demonstrated a differential expression of CYP1 enzymes and metabolic activation of pollutants in various endothelial linings suggesting that some but not all endothelial linings may be targets for xenobiotics metabolised by AhR-regulated enzymes. Studies on the effects of PCB126, 1-nitropyrene and BPA in cultured human primary endothelial cells demonstrated up-regulation of various biomarkers for endothelial dysfunction and cell stress suggesting that the human endothelium may be a sensitive target for these pollutants. The bioactivation and effects of environmental pollutants in endothelial cells should be further studied in order to unravel the role of these chemicals in human cardiovascular disease.

  • 137. Brown, Caleb Marshall
    et al.
    VanBuren, Collin S.
    Larson, Derek W.
    Brink, Kirstin S.
    Campione, Nicolas E.
    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.
    Vavrek, Matthew J.
    Evans, David C.
    Tooth counts through growth in diapsid reptiles: implications for interpreting individual and size-related variation in the fossil record2015In: Journal of Anatomy, ISSN 0021-8782, E-ISSN 1469-7580, Vol. 226, no 4, p. 322-333Article in journal (Refereed)
    Abstract [en]

    Tooth counts are commonly recorded in fossil diapsid reptiles and have been used for taxonomic and phylogenetic purposes under the assumption that differences in the number of teeth are largely explained by interspecific variation. Although phylogeny is almost certainly one of the greatest factors influencing tooth count, the relative role of intraspecific variation is difficult, and often impossible, to test in the fossil record given the sample sizes available to palaeontologists and, as such, is best investigated using extant models. Intraspecific variation (largely manifested as size-related or ontogenetic variation) in tooth counts has been examined in extant squamates (lizards and snakes) but is poorly understood in archosaurs (crocodylians and dinosaurs). Here, we document tooth count variation in two species of extant crocodylians (Alligator mississippiensis and Crocodylus porosus) as well as a large varanid lizard (Varanus komodoensis). We test the hypothesis that variation in tooth count is driven primarily by growth and thus predict significant correlations between tooth count and size, as well as differences in the frequency of deviation from the modal tooth count in the premaxilla, maxilla, and dentary. In addition to tooth counts, we also document tooth allometry in each species and compare these results with tooth count change through growth. Results reveal no correlation of tooth count with size in any element of any species examined here, with the exception of the premaxilla of C.porosus, which shows the loss of one tooth position. Based on the taxa examined here, we reject the hypothesis, as it is evident that variation in tooth count is not always significantly correlated with growth. However, growth trajectories of smaller reptilian taxa show increases in tooth counts and, although current samples are small, suggest potential correlates between tooth count trajectories and adult size. Nevertheless, interspecific variation in growth patterns underscores the importance of considering and understanding growth when constructing taxonomic and phylogenetic characters, in particular for fossil taxa where ontogenetic patterns are difficult to reconstruct.

  • 138. Brusatte, Stephen L.
    et al.
    Butler, Richard J.
    Niedzwiedzki, Grzegorz
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Sulej, Tomasz
    Bronowicz, Robert
    Satkunas, Jonas
    First record of Mesozoic terrestrial vertebrates from Lithuania: phytosaurs (Diapsida: Archosauriformes) of probable Late Triassic age, with a review of phytosaur biogeography2013In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 150, no 1, p. 110-122Article in journal (Refereed)
    Abstract [en]

    Fossils of Mesozoic terrestrial vertebrates from Lithuania and the wider East Baltic region of Europe have previously been unknown. We here report the first Mesozoic terrestrial vertebrate fossils from Lithuania: two premaxillary specimens and three teeth that belong to Phytosauria, a common clade of semiaquatic Triassic archosauriforms. These specimens represent an uncrested phytosaur, similar to several species within the genera Paleorhinus, Parasuchus, Rutiodon and Nicrosaurus. Because phytosaurs are currently only known from the Upper Triassic, their discovery in northwestern Lithuania (the Saltiskiai clay-pit) suggests that at least part of the Triassic succession in this region is Late Triassic in age, and is not solely Early Triassic as has been previously considered. The new specimens are among the most northerly occurrences of phytosaurs in the Late Triassic, as Lithuania was approximately 7-10. further north than classic phytosaur-bearing localities in nearby Germany and Poland, and as much as 40. further north than the best-sampled phytosaur localities in North America. The far northerly occurrence of the Lithuanian fossils prompts a review of phytosaur biogeography and distribution, which suggests that these predators were widely distributed in the Triassic monsoonal belt but rarer in more arid regions.

  • 139.
    Brännström, Ioana Onut
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Johannesson, Hanna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Tibell, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Thamnolia tundrae sp nov., a cryptic species and putative glacial relict2018In: The Lichenologist, ISSN 0024-2829, E-ISSN 1096-1135, Vol. 50, no 1, p. 59-75Article in journal (Refereed)
    Abstract [en]

    The lichen species of the genus Thamnolia, with their striking wormlike thalli and frequent occurrence in arctic and tundra environments, have often been debated with regard to the use of chemistry in lichen taxonomy. Phylogenetic studies have arrived at different conclusions as to the recognition of species in the genus, but in a recent study based on the analyses of six nuclear markers (genes or noncoding regions) of a worldwide sample of Thamnolia, we showed the existence of three well-supported lineages with two different chemistries and geographical distributions. Here, we present two analyses based on ITS and three markers, respectively, which were extended from the study mentioned above to include type specimens and additional Thamnolia strains and taxa. In these analyses the same three clades were retrieved. A putative DEAD-box helicase is used here for the first time as an informative phylogenetic marker to provide taxonomic resolution at species level. The distribution of morphological and chemical characters across the phylogeny was analyzed and it was concluded that three morphologically cryptic, but genetically well supported, species occur: T. vermicularis s. str., T. subuliformis s. str. and T. tundrae sp. nov. Thamnolia vermicularis s. str. contains individuals with uniform secondary chemistry (producing thamnolic acid) and a rather limited distribution in the European Alps, Tatra Mts and the Western Carpathians, a distribution which might result from glacial survival in an adjacent refugium/refugia. Thamnolia subuliformis s. str. is widely distributed in all hemispheres and the samples contain two chemotypes (either with thamnolic or squamatic acids). Thamnolia tundrae is described as new; it produces baeomycesic and squamatic acids, and has a distribution limited to the arctic tundra of Eurasia extending to the Aleutian Islands in North America. It may have survived the latest glaciation in coastal refugia near its present distribution. Thus, secondary chemistry alone is not suitable for characterizing species in Thamnolia, secondary chemistry and geographical origin are informative, and the ITS region can be confidently used for species recognition. Nomenclatural notes are given on several other names that have been used in Thamnolia.

  • 140.
    Buratovic, Sonja
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.