Bombus terrestris labial gland gene expression analysis

Marking pheromones (MPs) are used by the majority of male bumblebee species (Hymenoptera: Apidae), including a commercially important greenhouse pollinator, the buff-tailed bumblebee (Bombus terrestris), to attract conspecific females. The MP production in the cephalic part of the male bumblebee labial gland (LG) is a complex process involving biosynthesis of a multicomponent MP blend generally consisting of isoprenoids and fatty acid-derivatives. We employed a differential transcriptomic approach to identify candidate genes involved in the MP biosynthesis and its regulation by sequencing B. terrestris LG and a fat body (FB) transcriptomes. We have identified and investigated in detail more than 140 candidate genes presumably involved in MP biosynthesis such as carboxyl esterases, fatty acid reductases, enzymes involved in lipid binding, limited fatty acid chain shortening, and enzymes involved in production of isoprenoid MP components. The abundant and specific expression of genes connected to isoprenoid and FA biosynthesis and derivatization is consistent with the high abundances of these compounds in the MP. Herein identified candidate genes represent rational targets for future studies disentangling the molecular basis of MP biosynthesis.

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