title: Sex pheromone evolution is associated with differential regulation of the same desaturase gene in two genera of leafroller moths.
abstract: Chemical signals are prevalent in sexual communication systems. Mate recognition has been extensively studied within the Lepidoptera, where the production and recognition of species-specific sex pheromone signals are typically the defining character. While the specific blend of compounds that makes up the sex pheromones of many species has been characterized, the molecular mechanisms underpinning the evolution of pheromone-based mate recognition systems remain largely unknown. We have focused on two sets of sibling species within the leafroller moth genera Ctenopseustis and Planotortrix that have rapidly evolved the use of distinct sex pheromone blends. The compounds within these blends differ almost exclusively in the relative position of double bonds that are introduced by desaturase enzymes. Of the six desaturase orthologs isolated from all four species, functional analyses in yeast and gene expression in pheromone glands implicate three in pheromone biosynthesis, two Δ9-desaturases, and a Δ10-desaturase, while the remaining three desaturases include a Δ6-desaturase, a terminal desaturase, and a non-functional desaturase. Comparative quantitative real-time PCR reveals that the Δ10-desaturase is differentially expressed in the pheromone glands of the two sets of sibling species, consistent with differences in the pheromone blend in both species pairs. In the pheromone glands of species that utilize (Z)-8-tetradecenyl acetate as sex pheromone component (Ctenopseustis obliquana and Planotortrix octo), the expression levels of the Δ10-desaturase are significantly higher than in the pheromone glands of their respective sibling species (C. herana and P. excessana). Our results demonstrate that interspecific sex pheromone differences are associated with differential regulation of the same desaturase gene in two genera of moths. We suggest that differential gene regulation among members of a multigene family may be an important mechanism of molecular innovation in sex pheromone evolution and speciation.
authors.affiliation: The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Albre
authors.forename: Marjorie A
authors.initials: MA
authors.lastname: Liénard
authors.forename: Tamara M
authors.initials: TM
authors.lastname: Sirey
authors.forename: Silvia
authors.initials: S
authors.lastname: Schmidt
authors.forename: Leah K
authors.initials: LK
authors.lastname: Tooman
authors.forename: Colm
authors.initials: C
authors.lastname: Carraher
authors.forename: David R
authors.initials: DR
authors.lastname: Greenwood
authors.forename: Christer
authors.initials: C
authors.lastname: Löfstedt
authors.forename: Richard D
authors.initials: RD
authors.lastname: Newcomb
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000818:Animals; D000090943:Delta-5 Fatty Acid Desaturase; D019143:Evolution, Molecular; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics*; D049810:Genetic Speciation; D007915:Lepidoptera / Q000201:enzymology / Q000235:genetics*; D008393:Marriage; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012724:Sex Attractants / Q000096:biosynthesis / Q000235:genetics*; D012726:Sexual Behavior, Animal; D013045:Species Specificity; D013230:Stearoyl-CoA Desaturase
chemical_list: C587602:8-tetradecenyl acetate; D000085:Acetates; D000090943:Delta-5 Fatty Acid Desaturase; D005227:Fatty Acids; D012724:Sex Attractants; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C467901:acyl-CoA delta10-desaturase; C029627:delta-9 fatty acid desaturase