cDNA Sequence and Expression Pattern of the Putative Pheromone Carrier Aphrodisin

The cDNA sequence for aphrodisin, a lipocalin from hamster vaginal discharge which is involved in pheromonal activity, has been determined. Corresponding genomic clones were isolated and the promoter region was identified. Primer extension analysis revealed an adenosine residue as the main transcription initiation site, located 50 bp upstream of the translation start codon ATG, which is surrounded by a typical Kozak sequence. However, data from polymerase chain reaction analysis suggest the existence of at least one alternative transcription initiation site. The aphrodisin cDNA is 732 bp long and codes for the mature 151-aa aphrodisin and an additional N-terminal 16-aa secretory signal peptide. The 3' nontranslated region is 228 bp long. Among the known sequences, the aphrodisin cDNA shares the highest homology with the rat odorant-binding protein cDNA (45%), which verifies the protein data. Vaginal tissue and Bartholin's glands are the main aphrodisin gene-expressing tissues of the female hamster genital tract, as demonstrated by Northern blot analysis. Under less stringent hybridization conditions, RNA isolated from rat Bartholin's glands also showed a signal, indicating the occurrence of aphrodisin-related mRNA in this species.