Rodriguez-Leon, D. S.; Schmitt, T.; Pinto, M. A.; Thamm, M.; Scheiner, R.

Most terrestrial insects have a layer of cuticular hydrocarbons (CHCs) that protects them from desiccation and mediates chemical communication. CHC composition is regulated by the expression of genes coding for enzymes in the biosynthetic pathway of hydrocarbons. The diversity and expression of these enzymes determine the abundance and richness of compounds in the CHC profile of an insect. For instance, elongases and desaturases are enzymes that respectively lengthen the hydrocarbon chain and introduce double bonds into it. CHC profiles of honey bees (Apis mellifera) vary among castes, social roles, and subspecies. However, little is known about the genetic basis for this variation. Here, we examined the expression of specific elongase- and desaturase-encoding genes and correlated gene expression with CHC composition in nurse and forager bees of two highly divergent A. mellifera subspecies: A. m. carnica (lineage C) and A. m. iberiensis (lineage M). We provide evidence of the difference in specificity among specific desaturases and elongases and demonstrate how such differences shape the CHC profiles of A. mellifera workers during their transition from nursing to foraging. Our results expand the current understanding of the genetic basis of CHC biosynthesis and highlight the benefit of further investigating different subspecies of A. mellifera to better understand the mechanisms underlying the CHC diversity of honey bees`.