Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster V59
Eme David (1), Westfall Kristen M.(1), Kristjánsson Bjarni K.(2), Pálsson Snæbjörn (1)
1) Department of Life and Environmental Sciences, University of Iceland, Askja, Sturlugata 7, 101 Reykjavik, Iceland. 2)Department of Aquaculture and Fish Biology, Hόlar University College, Háeyri 1, 550 Sauðárkrόkur, Iceland
Kynnir / Presenter: David Eme
Tengiliður / Corresponding author: David Eme (davideme@hi.is)
The majority of phylogeographic studies rely on small fragments of mitochondrial DNA to infer evolutionary history of species, including clade relationships, dispersal events, demographic inferences or colonization routes. Nuclear DNA have, until recently, had a weak contribution in the understanding of phylogeographic patterns. Well-known processes such as incomplete lineage sorting, selection, genetic drift or introgression could lead to strong discrepancies between nuclear and mitochondrial genetic signals, thus, strongly affecting the phylogeographic patterns and the inferences about their underlying processes. Nuclear DNA has been used to infer either deep phylogenetic relationships between species or recent divergence between populations using e.g. microsatellite data. Fast evolving nuclear markers, such as intronic regions, that are useful for inferring phylogeographic history, have been difficult to obtain until the last few years. However, the advent of high throughput sequencing technology and recent development of the restriction-site-associated DNA sequencing (RADSeq) method offer the possibility to open the door to reconstruct the evolutionary history of populations to an unprecedented level thanks to the abundance of nuclear data. RADSeq is a genotyping method that uses restriction enzymes and next generation sequencing platforms to sample single nucleotide polymorphisms (SNPs) within hundreds or thousands of loci throughout the genome at putatively homologous short DNA fragments (loci) across individuals. In this study, we used two mitochondrial genes (16S and COI) and double digest paired-end RADSeq genomic data to contrast the phylogeographic signals of five mitochondrial clades, or even cryptic species, of an Icelandic groundwater amphipod species (Crangonyx islandicus) that survived in Iceland beneath the glacier during the Pleistocene1. First, we used a Bayesian structured coalescent method to reconstruct the mitochondrial coalescent tree taking into account dispersal among clades and estimates of the present day effective population size of the different clades. Second, to contrast the mitochondrial signal, we performed population genetic analyses, multivariate and Bayesian assignment approaches to infer the population structure and clade relationships from RADSeq data using various unlinked SNPs and multi-allelic locus information. 1: Kornobis et al.· 2010. Molecular Ecology 19: 2516-2530.