Pheromone-binding protein and general odorant-binding protein of Sesamia nonagrioides:: sex- and diel-dependent expression

The expression of a pheromone-binding protein (PBP) and a general odorant-binding protein (GOBP) in Sesamia nonagrioides (Lef.) (Lepidoptera: Noctuidae) was studied. Lymantria dispar's PBP1 antibody yielded an immunoreactive band with an apparent MW of approximately 14.8 kDa, present specifically in the antennae of both sexes, with males having approximately three-fold the quantity found in females. Furthermore, Manduca sexta's odorant-binding protein-2 (GOBP2) antibody recognized a band at approximately 14.5 kDa in the antennae of both sexes. Levels of both proteins were compared between scotophase and photophase periods in insects that were raised under L16:D8 or under constant light. The level of GOPB2 was significantly lower in both sexes during photophase and continuous light; whereas the level of the PBP was significantly lower in females' antennae, in males' antennae it remained at the same level as that found during the scotophase.