Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017

Erindi/veggspjald / Talk/poster E83

Contrasting population genetic patterns within the groundwater amphipod Crangonyx islandicus

Höfundar / Authors: David Eme (1,2), Kristen M. Westfalls (1,3), Bjarni K. Kristjánsson (4), Snæbjörn Pálsson (1)

Starfsvettvangur / Affiliations: 1, Háskóli Íslands, 2, Massey University New Zealand 3, Pacific Biological Station, Fisheries and Oceans Canada, 4 Háskólinn á Hólum

Kynnir / Presenter: Snæbjörn Pálsson

An endemic species of a groundwater amphipods, Crangonyx islandicus, was discovered in 1998 in springs in lavafields of the volcanic zone in Iceland. Genetic analyses has revealed different patterns in variation of mtDNA than for the nuclear internal transcribed spacer (ITS) region. The mtDNA represents five distinct monophyletic mtDNA lineages within Iceland which follow the geographic distances between the sample sites, supporting an existence of subglacial refugia. The mtDNA lineage from northeast Iceland diverged from the other 4.8 Myrs ago, including a split from other samples from north Iceland. Patterns in the ITS marker suggest however that the oldest split is between populations from north and south Iceland. Genome wide analysis (ddRadSeq) of 60 individuals was conducted to analyze this discrepancy. Various statistical methods were applied to capture different information in the data, including partitioning of the variance among groups, ordination of individuals and assignment probabilities, incomplete lineage sorting and phylogenetic analysis of multiple polymorphic sites. Majority of the nuclear markers and of the statistical methods applied supported the split observed for the ITS region, indicating ancestral admixture of the populations in north Iceland. Five markers showed signs of natural selection, including a fragment of the mtDNA.