Abstract
Insect cuticular compounds serve multiple functions. As important intersexual signaling chemicals, they show variation between the sexes, but little is known about the underlying molecular mechanisms. Here, we report that sexually dimorphic hydrocarbons (SDHCs) are generated by a fatty acid elongase gene that is regulated by sex-differentiation genes in the German cockroach, Blattella germanica. Sexually mature females possess more C29 cuticular hydrocarbons (CHCs), especially the contact sex pheromone precursor 3,11-DimeC29. An RNAi screen and heterologous expression revealed that BgElo12 and BgElo24 were involved in HC production, but only BgElo12 was responsible for SDHCs. Repressing female-enriched BgElo12 masculinized the female CHC profile, decreased contact sex pheromone level, and reduced the female’s sexual attractiveness. Moreover, RNAi of the sex-differentiation genes BgTra or BgDsx modulated both BgElo12 transcripts and CHC profiles in females and males. The SDHCs are shaped by sexual selection, as females use them to keep high levels of sex pheromone.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
E-mail addresses: X.-J. Pei: xiaojinpei{at}nwafu.edu.cn, Y.-L. Fan: yfan{at}nwafu.edu.cn T.-X. Liu: txliu{at}nwafu.edu.cn