Genome evolution, ecological adaptation and speciation
Genome-wide variation in recently diverged populations can reveal molecular signatures reflecting the processes driving adaptive evolution and speciation. The three-spined stickleback is a useful vertebrate model to investigate genome evolution during population differentiation and ecological adaptation; freshwater colonization has repeatedly occurred since the last glaciation giving rise to recurrent phenotypic diversification and locally-adapted ecotypes.
As part of a consortium headed by Manfred Milinski, we carried out comparative & population genomics analyses and immunological transcriptomics to assess the extent of genome-wide differentiation among pairs of lake-river ecotypes. Results indicate that selection is a major contributor to the observed heterogeneous patterns of genomic divergence, and that structural variation substantially contributes to genetic variation. Young genes such as recently duplicated genes are overrepresented among copy-number variations (CNVs), and are enriched with functional roles related to environmental response. These young duplicates provide ample raw genetic material that may be used for adaptation to novel environments.