title: The evolution of desaturase gene regulation involved in sex pheromone production in leafroller moths of the genus planotortrix.
abstract: The evolution of mating systems in leafroller moths involves differential regulation of a desaturase gene that produces distinct sex pheromones. In the genus Planotortrix, female P. octo predominantly emits (Z)-8-tetradecenyl acetate due to the expression of desat5 in their pheromone glands, whereas female P. excessana produces a blend of (Z)-5- and (Z)-7-tetradecenyl acetate and does not express desat5. In this study, F1 females from interspecific crosses of these species and F1 backcrosses to P. excessana expressed little, if any, desat5 in their pheromone glands, whereas F1 backcrosses to P. octo and F2 crosses displayed a range of expression levels of desat5, consistent with the action of a trans-acting repressor from P. excessana. Females expressing desat5 always produced (Z)-8-tetradecenyl acetate, and the presence of at least one P. octo-like allele of desat5 was required for the expression of desat5, suggesting a cis-regulatory factor from P. octo is necessary. Comparison of 1148bp upstream of the desat5 open reading frame revealed 35 differences, including a 7-bp insertion in P. octo. We argue these data best fit a model of pheromone evolution that involves changes in a trans-acting repressor and a cis-regulatory mutation in an activator binding site within the desat5 promoter.
authors.affiliation: Molecular Sensing Team, Food Innovation, The New Zealand Institute for Plant & Food Research, Auckland 1142, New Zealand.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Albre
authors.forename: Bernd
authors.initials: B
authors.lastname: Steinwender
authors.forename: Richard David
authors.initials: RD
authors.lastname: Newcomb
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000818:Animals; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005229:Fatty Acids, Monounsaturated; D005260:Female; D005786:Gene Expression Regulation; D014644:Genetic Variation; D009036:Moths / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic; D012724:Sex Attractants / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C587602:8-tetradecenyl acetate; D000085:Acetates; D005229:Fatty Acids, Monounsaturated; D012724:Sex Attractants; D044943:Fatty Acid Desaturases; C467901:acyl-CoA delta10-desaturase
keywords: Planotortrix; desaturase; evolution; gene regulation; leafroller moth; repressor sex pheromone