Abstracts (first author)
Genomic islands of divergence: a comparison of five parapatric lake-river population pairs of three-spined sticklebacks
Sticklebacks have recently colonized various freshwater habitats and have since undergone recurrent phenotypic divergence. Here, we sample five geographically distinct lake-river population pairs of the three-spined stickleback for investigating patterns of population divergence at varying stages of ecological speciation. Using 60 whole genome sequences (15x coverage each) we identify genomic islands of divergence between parapatric lake-river ecotypes. This allows us to evaluate the number, size and distribution of genomic islands of divergence between several population pairs and to assess the extent of population differentiation across our samples. We identify different genes and genomic regions potentially associated with ecological differentiation in the five lake-river comparisons. This suggests that divergence patterns between lakes and rivers can involve multiple molecular pathways. Interestingly, we find some associations between genomic structural variations and islands of divergence. This is based on our extensive set of structural variations including deletions, copy-number variations, inversions, and translocations. Combined with estimates of the recombination rates across the genomes, we provide insights into the relevance of the genomic architecture and the role of genomic islands during adaptive divergence.