D3447: Genomic regions underlying the species-specific mating songs of green lacewings

Rapid species radiations provide insight into the process of speciation and diversification. The radiation of the Chrysoperla carnea-group lacewings seems to be driven, at least in part, by their species-specific pre-mating vibrational duets. We associated genetic markers from across the genome with song period phenotype in the offspring of a laboratory cross between Chrysoperla plorabunda and Chrysoperla adamsi, two species primarily differentiated by their mating songs. Two genomic regions were strongly associated with the song period phenotype. Large regions of chromosomes one and two were associated with song phenotype as fewer recombination events occurred on the song-associated chromosomes relative to the other autosomes. Candidate genes were identified by functional annotation of proteins from the C. carnea reference genome. The majority of genes associated with vibrational courtship signals in Drosophila were found on the lacewing song-associated chromosomes one and two. Using wild-caught individuals from both species, we identified signals of genomic divergence on the song-associated chromosomes. We identified several promising candidate genes both in song-associated regions and near divergence outliers. Together these findings bring us one step closer to identifying the genomic basis of a mating song trait critical to the maintenance of species boundaries in green lacewings.