SEPARATION, CHARACTERIZATION AND SEXUAL HETEROGENEITY OF MULTIPLE PUTATIVE ODORANT-BINDING PROTEINS IN THE HONEYBEE APIS-MELLIFERA L. (HYMENOPTERA, APIDEA)

According to precise molar mass determined by mass spectrometry and N- terminal sequence, some 25 odorant-binding-like proteins were characte rized from the antennae and legs of worker and drone honeybees. Antenn al specific proteins, composed of six different molecules, were classi fied into three subclasses according to N-terminal sequence homology. The major sexual difference was shown to lie in the relative abundance of these antennal specific proteins and in the occurrence of a drone- specific isoform. At least 19 other related proteins were found to occ ur in antennae and legs, forming another class showing homology with i nsect OBP. Genotype comparison of two honeybee races revealed a variab ility limited to this second class. Provided that these odorant-bindin g-like proteins are indeed able to bind odorants or pheromones, the qu estion of whether their peculiar multiplicity contributes to the remar kable capacity of the honeybee to discriminate among a wide range of o dor molecules is raised.