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Alpine crossroads or origin of genetic diversity? Comparative phylogeography of two sympatric microgastropod species.

Weigand AM, Pfenninger M, Jochum A, Klussmann-Kolb A - PLoS ONE (2012)

Bottom Line: Consequently, we identify the Alpine Region as a significant 'hot-spot' for the formation of genetic diversity within European Carychium lineages.Passive dispersal via anthropogenic means best explains the presence of transatlantic European Carychium populations on the Azores and in North America.We conclude that passive (anthropogenic) transport could mislead the interpretation of observed phylogeographical patterns in general.

View Article: PubMed Central - PubMed

Affiliation: Department of Phylogeny and Systematics, Goethe University, Frankfurt am Main, Hesse, Germany. A.Weigand@bio.uni-frankfurt.de

ABSTRACT
The Alpine Region, constituting the Alps and the Dinaric Alps, has played a major role in the formation of current patterns of biodiversity either as a contact zone of postglacial expanding lineages or as the origin of genetic diversity. In our study, we tested these hypotheses for two widespread, sympatric microgastropod taxa--Carychium minimum O.F. Müller, 1774 and Carychium tridentatum (Risso, 1826) (Gastropoda, Eupulmonata, Carychiidae)--by using COI sequence data and species potential distribution models analyzed in a statistical phylogeographical framework. Additionally, we examined disjunct transatlantic populations of those taxa from the Azores and North America. In general, both Carychium taxa demonstrate a genetic structure composed of several differentiated haplotype lineages most likely resulting from allopatric diversification in isolated refugial areas during the Pleistocene glacial periods. However, the genetic structure of Carychium minimum is more pronounced, which can be attributed to ecological constraints relating to habitat proximity to permanent bodies of water. For most of the Carychium lineages, the broader Alpine Region was identified as the likely origin of genetic diversity. Several lineages are endemic to the broader Alpine Region whereas a single lineage per species underwent a postglacial expansion to (re)colonize previously unsuitable habitats, e.g. in Northern Europe. The source populations of those expanding lineages can be traced back to the Eastern and Western Alps. Consequently, we identify the Alpine Region as a significant 'hot-spot' for the formation of genetic diversity within European Carychium lineages. Passive dispersal via anthropogenic means best explains the presence of transatlantic European Carychium populations on the Azores and in North America. We conclude that passive (anthropogenic) transport could mislead the interpretation of observed phylogeographical patterns in general.

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COI haplotype networks for Carychium minimum (A) and C. tridentatum (B).The respective nesting is indicated as a thin (1st level), thick (2nd level) and thick dotted line (3rd level). The applied nesting design is color coded, with colored boxes indicating taxon-specific molecular operational taxonomic units (MOTUs). Haplotypes are numbered consecutively and possess an area relative to their frequency in the total dataset. Lines and filled circles interconnecting haplotypes represent the mutational pathway and the amount of mutational steps between them.
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pone-0037089-g003: COI haplotype networks for Carychium minimum (A) and C. tridentatum (B).The respective nesting is indicated as a thin (1st level), thick (2nd level) and thick dotted line (3rd level). The applied nesting design is color coded, with colored boxes indicating taxon-specific molecular operational taxonomic units (MOTUs). Haplotypes are numbered consecutively and possess an area relative to their frequency in the total dataset. Lines and filled circles interconnecting haplotypes represent the mutational pathway and the amount of mutational steps between them.

Mentions: Results of the resolved Median-Joining and Statistical Parsimony network are identical (Fig. 3A). The observed 39 haplotypes for CM can be divided into 5 MOTUs (CMMOTU1 – CMMOTU5) following the results of a 3rd level nesting. CMMOTU1 demonstrates a star-like topology comprising the most frequent haplotype H1 (Table 1) and is the most spatially widespread (Fig. 4A). Haplotypes are distributed over southeastern (Dinaric Alps, Balkan Mountains), Central (e.g. Germany, Belgium) and Northern Europe (e.g. Great Britain and Sweden), where in the latter region this MOTU can exclusively be found. All other MOTUs form more spatially restricted genetic entities. Among these, CMMOTU4 shows the widest distribution with haplotypes located in southern France, the Alps, the Dinaric Alps and south/southwestern Germany. Haplotypes of the other three MOTUs are restricted to the Carpathians (CMMOTU2), northern Spain (CMMOTU3) and the Alpine Region (CMMOTU3+CMMOTU5). Haplotypes of CMMOTU5 are also present at two localities on the Black Sea coast (Table 1: PT, TR).


Alpine crossroads or origin of genetic diversity? Comparative phylogeography of two sympatric microgastropod species.

Weigand AM, Pfenninger M, Jochum A, Klussmann-Kolb A - PLoS ONE (2012)

COI haplotype networks for Carychium minimum (A) and C. tridentatum (B).The respective nesting is indicated as a thin (1st level), thick (2nd level) and thick dotted line (3rd level). The applied nesting design is color coded, with colored boxes indicating taxon-specific molecular operational taxonomic units (MOTUs). Haplotypes are numbered consecutively and possess an area relative to their frequency in the total dataset. Lines and filled circles interconnecting haplotypes represent the mutational pathway and the amount of mutational steps between them.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3351404&req=5

pone-0037089-g003: COI haplotype networks for Carychium minimum (A) and C. tridentatum (B).The respective nesting is indicated as a thin (1st level), thick (2nd level) and thick dotted line (3rd level). The applied nesting design is color coded, with colored boxes indicating taxon-specific molecular operational taxonomic units (MOTUs). Haplotypes are numbered consecutively and possess an area relative to their frequency in the total dataset. Lines and filled circles interconnecting haplotypes represent the mutational pathway and the amount of mutational steps between them.
Mentions: Results of the resolved Median-Joining and Statistical Parsimony network are identical (Fig. 3A). The observed 39 haplotypes for CM can be divided into 5 MOTUs (CMMOTU1 – CMMOTU5) following the results of a 3rd level nesting. CMMOTU1 demonstrates a star-like topology comprising the most frequent haplotype H1 (Table 1) and is the most spatially widespread (Fig. 4A). Haplotypes are distributed over southeastern (Dinaric Alps, Balkan Mountains), Central (e.g. Germany, Belgium) and Northern Europe (e.g. Great Britain and Sweden), where in the latter region this MOTU can exclusively be found. All other MOTUs form more spatially restricted genetic entities. Among these, CMMOTU4 shows the widest distribution with haplotypes located in southern France, the Alps, the Dinaric Alps and south/southwestern Germany. Haplotypes of the other three MOTUs are restricted to the Carpathians (CMMOTU2), northern Spain (CMMOTU3) and the Alpine Region (CMMOTU3+CMMOTU5). Haplotypes of CMMOTU5 are also present at two localities on the Black Sea coast (Table 1: PT, TR).

Bottom Line: Consequently, we identify the Alpine Region as a significant 'hot-spot' for the formation of genetic diversity within European Carychium lineages.Passive dispersal via anthropogenic means best explains the presence of transatlantic European Carychium populations on the Azores and in North America.We conclude that passive (anthropogenic) transport could mislead the interpretation of observed phylogeographical patterns in general.

View Article: PubMed Central - PubMed

Affiliation: Department of Phylogeny and Systematics, Goethe University, Frankfurt am Main, Hesse, Germany. A.Weigand@bio.uni-frankfurt.de

ABSTRACT
The Alpine Region, constituting the Alps and the Dinaric Alps, has played a major role in the formation of current patterns of biodiversity either as a contact zone of postglacial expanding lineages or as the origin of genetic diversity. In our study, we tested these hypotheses for two widespread, sympatric microgastropod taxa--Carychium minimum O.F. Müller, 1774 and Carychium tridentatum (Risso, 1826) (Gastropoda, Eupulmonata, Carychiidae)--by using COI sequence data and species potential distribution models analyzed in a statistical phylogeographical framework. Additionally, we examined disjunct transatlantic populations of those taxa from the Azores and North America. In general, both Carychium taxa demonstrate a genetic structure composed of several differentiated haplotype lineages most likely resulting from allopatric diversification in isolated refugial areas during the Pleistocene glacial periods. However, the genetic structure of Carychium minimum is more pronounced, which can be attributed to ecological constraints relating to habitat proximity to permanent bodies of water. For most of the Carychium lineages, the broader Alpine Region was identified as the likely origin of genetic diversity. Several lineages are endemic to the broader Alpine Region whereas a single lineage per species underwent a postglacial expansion to (re)colonize previously unsuitable habitats, e.g. in Northern Europe. The source populations of those expanding lineages can be traced back to the Eastern and Western Alps. Consequently, we identify the Alpine Region as a significant 'hot-spot' for the formation of genetic diversity within European Carychium lineages. Passive dispersal via anthropogenic means best explains the presence of transatlantic European Carychium populations on the Azores and in North America. We conclude that passive (anthropogenic) transport could mislead the interpretation of observed phylogeographical patterns in general.

Show MeSH
Related in: MedlinePlus