To gain insights into the molecular mechanisms that mediate sexually dimorphic chemoreception, we used a male-enriched antennal cDNA probe to isolate genes from antennae of the brownbanded cockroach, Supella longipalpa. Fifty cDNA inserts were sequenced from a male antennal library and their Drosophila homologues identified. Eight inserts encoded putative odorant or pheromone binding proteins (OBPs/PBPs). Sequence alignments and phylogenetic analysis show that these proteins share 76%–96% sequence identity with six conserved cysteines at characteristic positions and group into three families. Northern blots and in situ hybridization identified two OBPs/PBPs that are enriched in male antennae, and one of these is expressed almost exclusively in male antennae. Antibodies against this protein, Slon OBP4, reveal an 18 kD polypeptide with upregulated expression in adult males and extensive expression in supporting cells throughout the antenna. In female antennae OBP4 is expressed in only a few cells at similar positions in successive antennal segments. These observations suggest that OBP4 may participate in sex pheromone recognition in males, and demonstrate functional subdivisions within female olfactory sensilla. We also isolated cDNAs encoding membrane receptors and signaling proteins, a variety of structural proteins and enzymes, and proteins of unknown function. These gene products represent the first chemosensory genes described in male cockroaches using a molecular genetic approach, and together with an OBP recently isolated from females of the cockroach Leucophaea maderae, they suggest that OBPs appeared early in the evolution of Pterygote insects.
Species 1: Blattodea Blattellidae Supella longipalpa (brownbanded cockroach)
Keywords: pheromone
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