Sex-pheromone biosynthesis

Understanding biosynthetic semiochemical pathways in insects and determining the stereoselectivity of those transformations will contribute to the characterization of reaction centers of the corresponding enzymes. In a biosynthetic study of labial gland-derived patrolling pheromones in bumblebees in cooperation with the Institute of Organic Chemistry and Biochemistry, Prague, delta-9 desaturase from the labial gland was cloned and functionally characterized after expressions in yeast cells (Matoušková et al. 2008 ChemBioChem). In a Manduca sexta sex pheromone desaturases project a new desaturase gene (MsD3) was cloned and found to be closely related to previously characterized 1,4-conjugase (MsD2). This putative 1,6-conjugase responsible for formation of conjugated trienes, important components of the sex pheromone blend, was not yet fully functionally characterized and the final proof of trienes formation is still missing. However, a point mutation study, domains swapping and creating a chimeric desaturase demonstrated that one AA residue is responsible for the change of specificity.

After completing the structural characterization of MsD3 other enzymes involved in the sex pheromone blend formation will be characterized. We will use next generation sequencing of cDNAs from different organs of M. sexta females and males, and the obtained data will be compared to in-parallel sequenced Spodoptera species (in a cooperation with the Department of Entomology). This study should shed light on the enzymatic apparatus of sex pheromone formation in Lepidoptera. After identifying the putative genes the functional assay will be performed using our analytical capabilities both for M. sexta and Spodoptera species.