uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Diversity Underfoot: Systematics and Biogeography of the Dictyostelid Social Amoebae
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Dictyostelids (Amoebozoa) are a group of social amoebae consisting of approximately 150 species, which are found in terrestrial habitats worldwide. They are divided into eight major clades based on molecular phylogeny, and within these clades are many species complexes. Some species are seemingly cosmopolitan in distribution, while others are geographically restricted. In this thesis dictyostelids were recovered from high latitude habitats (soils in Sweden and Iceland) as well as from the soles of shoes. Morphological characters and DNA sequence analyses were used to identify isolates that were recovered and delimit new species, as well as to investigate the monophyly of Dictyostelium aureostipes. Nine species were reported from Northern Sweden and four from Iceland. Among the isolates recorded in Sweden were two new species, described as D. barbibulus and Polysphondylium fuscans. P. fuscans was among the four species recovered from footwear, contributing evidence for anthropogenic transport of dictyostelids. Ecological patterns were assessed using linear regression and generalized linear models. The ecological analyses of dictyostelids recovered from Iceland indicate that these organisms are most frequently found in soils of near-neutral pH, but also exhibit a species richness peak in moderately acidic soils. These analyses indicate that in Iceland dictyostelid species richness decreases with altitude, and in the northern hemisphere the species richness increases with decreasing latitude. A three-region analysis of the D. aureostipes species complex indicated that this species is in fact made up of at least five phylogenetically distinct clades, and in light of this the group is in need of taxonomic revision. These results indicate that the dictyostelid species richness is higher than previously known, especially in high-latitude regions, and that even seemingly well-defined species may harbour cryptic diversity. Presently, species ranges may be expanding via anthropogenic dispersal but despite this, the dictyostelids are found to exhibit biogeographic trends well known from macroorganisms, such as a latitudinal gradient of species richness.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2013. , 56 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1097
Keyword [en]
Amoeba, biogeography, cryptic species, dictyostelid, latitudinal gradient, multicellularity, protist, social amoeba, phylogenetics, systematics, new species
National Category
Biological Systematics Microbiology
Research subject
Biology with specialization in Systematics
URN: urn:nbn:se:uu:diva-210074ISBN: 978-91-554-8804-8OAI: oai:DiVA.org:uu-210074DiVA: diva2:660773
Public defence
2013-12-13, Lindahlsalen, Norbyvägen 18D, Uppsala, 10:00 (English)
Available from: 2013-11-22 Created: 2013-10-30 Last updated: 2014-06-16
List of papers
1. What's on your boots: an investigation into the role we play in protist dispersal
Open this publication in new window or tab >>What's on your boots: an investigation into the role we play in protist dispersal
2012 (English)In: Journal of Biogeography, ISSN 0305-0270, E-ISSN 1365-2699, Vol. 39, no 5, 998-1003 p.Article in journal, Letter (Refereed) Published
Abstract [en]

D. M. Wilkinson (2010, Journal of Biogeography, 37, 393–397) suggested that anthropogenic dispersal is an understudied and potentially important factor in terrestrial protist biogeography. We investigated human footwear as a potential vector of dictyostelids, a diverse group of amoebae that includes both geographically restricted and cosmopolitan species. Eighteen pairs of boots were examined and dictyostelids were isolated from nearly all samples larger than 5.0 g. In total, six dictyostelid isolates were recovered, corresponding to four species –Dictyostelium minutum, D. sphaerocephalum, D. leptosomopsis and a new species, Polysphondylium sp. 1. Myxogastrid amoebae and acrasid-like aggregations were also observed. Thus anthropogenic dispersal of naked amoebae appears to occur. The possible role of variations in dictyostelid fruiting body morphologies in dispersal potential is also discussed. These results support Wilkinson’s proposal and suggest that dictyostelids may be a useful group with which to study anthropogenic dispersal of terrestrial protists.

Anthropogenic biogeography, Dictyostelium, dispersal vectors, global dispersal, protist distribution, social amoebae, terrestrial microorganisms
National Category
Other Biological Topics
urn:nbn:se:uu:diva-169502 (URN)10.1111/j.1365-2699.2012.02691.x (DOI)000302910600016 ()
Available from: 2012-03-01 Created: 2012-03-01 Last updated: 2014-01-23Bibliographically approved
2. Diversity of dictyostelid social amoebae in high latitude habitats of Northern Sweden
Open this publication in new window or tab >>Diversity of dictyostelid social amoebae in high latitude habitats of Northern Sweden
2013 (English)In: Fungal diversity, ISSN 1560-2745, Vol. 58, no 1, 185-198 p.Article in journal (Refereed) Published
Abstract [en]

The dictyostelid social amoebae (Dictyostelia) occur in terrestrial habitats worldwide. It has been observed previously that their diversity decreases with increasing latitude and altitude. Here we look at dictyostelid diversity in the high latitude habitats of Northern Sweden. Dictyostelids were recovered from soil samples using traditional plating methods and then identified using morphological characters and molecular sequence (small subunit ribosomal RNA) data. In total, nine species were recovered, including two new species, described herein as Dictyostelium barbibulus and Polysphondylium fuscans. The species diversity found here is discussed in relation to previous findings in the area as well as other high-latitude studies, and biogeographical patterns are examined. The total number of species found in Northern Sweden is lower than the numbers recorded for regions further south in Europe, a finding consistent with a latitudinal gradient of species diversity. Our findings highlight the benefit of using molecular data for accurate species identification in Dictyostelia and the need for a continued sampling effort to better understand their diversity and distribution, especially in high latitude habitats.

National Category
Biological Systematics
urn:nbn:se:uu:diva-187570 (URN)10.1007/s13225-012-0208-3 (DOI)000313366900012 ()
Available from: 2012-12-07 Created: 2012-12-07 Last updated: 2014-01-23Bibliographically approved
3. Everything is not everywhere: a latitudinal gradient of protist diversity
Open this publication in new window or tab >>Everything is not everywhere: a latitudinal gradient of protist diversity
(English)Manuscript (preprint) (Other academic)
National Category
urn:nbn:se:uu:diva-209766 (URN)
Available from: 2013-10-25 Created: 2013-10-25 Last updated: 2014-01-23
4. The  yellow  slime  mold  is  a  red  herring:  large  hidden  diversity  in  a  single  protist  morphospecies
Open this publication in new window or tab >>The  yellow  slime  mold  is  a  red  herring:  large  hidden  diversity  in  a  single  protist  morphospecies
(English)Manuscript (preprint) (Other academic)
National Category
Biological Systematics
urn:nbn:se:uu:diva-209765 (URN)
Available from: 2013-10-25 Created: 2013-10-25 Last updated: 2014-01-23

Open Access in DiVA

fulltext(1729 kB)502 downloads
File information
File name FULLTEXT01.pdfFile size 1729 kBChecksum SHA-512
Type fulltextMimetype application/pdf
Buy this publication >>

Search in DiVA

By author/editor
Perrigo, Allison L
By organisation
Systematic Biology
Biological SystematicsMicrobiology

Search outside of DiVA

GoogleGoogle Scholar
Total: 502 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 855 hits
ReferencesLink to record
Permanent link

Direct link