Lipases and carboxylesterases are involved in interspecific pheromone differences between two moth species

Abstract

Moth sex pheromones are a classical model for studying sexual selection. Females produce a species-specific pheromone blend that attracts males. Revealing the enzymes involved in the interspecific variation in blend composition is key for understanding the evolution of these sexual communication systems. The nature of the enzymes involved in the variation of acetate esters, which are prominent compounds in moth pheromone blends, remains unclear. We identified enzymes involved in acetate metabolism in two closely related species: Heliothis (Chloridea) subflexa and H. (C.) virescens, which differ in production of acetate esters. Through comparative transcriptomic analyses and CRISPR/Cas9 knockouts, we showed that two lipases and two esterases induce lower levels of acetate esters in female pheromones. To place our findings in an evolutionary context, we explored the molecular evolution of related lipases and esterases in Lepidoptera. Together, our results show that lipases and carboxylesterases are unexpectedly involved in tuning Lepidoptera pheromones composition.

More to legs than meets the eye: Presence and function of pheromone compounds on heliothine moth legs

“…To determine expression levels of sex pheromone biosynthesis‐related genes, we conducted qPCR experiments with primers of the following genes: d11 , carboxylesterase 21 ( cxe21 , also known as HsTED ), a lipase ( lipX ) and another esterase ( est1 ). We chose these genes because previous QTL analysis, RNA‐Seq and CRISPR experiments have indicated that these genes play a role in the biosynthesis of sex pheromone compounds in heliothine moths (De Fouchier et al, 2022; Fruitet et al, 2022; Groot et al, 2009; Vogel et al, 2010). Since cxe21 , lipX and est1 have recently been identified as players in the synthesis and degradation of acetate esters (De Fouchier et al, 2022; Fruitet et al, 2022), we expected to find these genes expressed in tissues producing pheromone compounds.…”

“…We chose these genes because previous QTL analysis, RNA‐Seq and CRISPR experiments have indicated that these genes play a role in the biosynthesis of sex pheromone compounds in heliothine moths (De Fouchier et al, 2022; Fruitet et al, 2022; Groot et al, 2009; Vogel et al, 2010). Since cxe21 , lipX and est1 have recently been identified as players in the synthesis and degradation of acetate esters (De Fouchier et al, 2022; Fruitet et al, 2022), we expected to find these genes expressed in tissues producing pheromone compounds. Primers for the target genes were designed using Primer 3 Web version (primer3_results.cgi release 4.1.0) (see Supporting Information).…”

“…The genes cxe21, est1 and lipX have recently been identified as putative genes involved in sex pheromone metabolism in C. subflexa (De Fouchier et al, 2022;Fruitet et al, 2022). As these candidate genes may be involved in acetate-ester synthesis as well as acetateester degradation (De Fouchier et al, 2022;Fruitet et al, 2022), we refrain from drawing any conclusions about their role in pheromone biosynthesis and considered our analysis as a first indication that pheromone-biosynthesis genes are also expressed in moth leg tissue. Dou et al (2019Dou et al ( , 2020 already demonstrated that 16:Ald is locally produced in legs of H. zea.…”