Genetics of cuticular hydrocarbon differences between males of the parasitoid wasps Nasonia giraulti and Nasonia vitripennis.

Many insects rely on cuticular hydrocarbons (CHCs) as major recognition signals between individuals. Previous research on the genetics of CHCs has focused on Drosophila in which the roles of three desaturases and one elongase were highlighted. Comparable studies in other insect taxa have not been conducted so far. Here, we explore the genetics of CHCs in hybrids of the jewel wasps Nasonia giraulti and Nasonia vitripennis. We analyzed the CHC profiles of pure strain and of F(2) hybrid males using gas chromatography coupled with mass spectrometry and distinguished 54 peaks, of which we identified 52 as straight-chain, monounsaturated, or methyl-branched CHCs. The latter compound class proved to be particularly abundant and diverse in Nasonia. Quantitative trait locus (QTL) analysis suggests fixed genetic differences between the two strains in 42 of the 54 studied traits, making Nasonia a promising genetic model for identifying genes involved in CHC biosynthesis. QTL for methyl-branched CHCs partly clustered in genomic regions with high recombination rate: a possible indication for pleiotropic genes that control their biosynthesis, which is largely unexplored so far. Finally, we identified and mapped genes in the Nasonia genome with high similarity to genes that have been implicated in alkene biosynthesis in Drosophila and discuss those that match in their position with predicted QTL for alkenes.