In project SpecIAnt we study speciation using hybridizing wood ants as a model system. We focus on the recently diverged Formica rufa group wood ants, many of which occur in Southern Finland with overlapping distributions.
Our studies have uncovered a unique consequence of hybridization, where hybrid females are favored but males suffer from hybrid breakdown. This differential natural selection is likely caused by the fact that females are diploid and males are haploid. In haploid males all the recessive problems of hybridization are exposed to selection. This makes ants a good model system for speciation genomics; genomic regions that prevent gene flow and lead to reproductive isolation are easy to identify.
Our current studies have identified several candidate barrier loci, that prevent gene flow between diverging species. Now we are confirming these candidates and testing if natural selection is actually acting on these loci in nature. At the same time we are utilizing large-scale individual level transcriptome data set that will elucidate which gene expression patterns lead to hybrid breakdown in the males. We are also interested in how methylation contributes to hybrid dysfunction and the role of epigenetics in speciation.