The golden hamster aphrodisin gene - Structure, expression in parotid glands of female animals, and comparison with a similar murine gene

The so-called lipocalins are a family of extracellular proteins that are kn own to typically fulfill tasks as transport proteins for small hydrophobic molecules. However, in the last decade, a large diversity has been describe d concerning their functions, for example as enzymes, immunomodulators, or proteins involved in coloration and pheromone action. Aphrodisin belongs to those lipocalins, which are of significant importance for the pheromonal s timulation of copulatory behavior in male hamsters, We recently succeeded i n characterizing the corresponding cDNA and demonstrated the expression of the aphrodisin gene in the vagina, uterus, and Bartholin's glands of female hamsters, Here we report the structure of the aphrodisin gene and the func tionality of its promoter region. We further compare the aphrodisin gene to the related gene for mouse odorant binding protein la, indicating similar functions of their products. As a novelty, we show that the aphrodisin gene , in addition to the above-mentioned tissues, is also expressed in female h amster parotid glands. In contradiction to the results expected, we finally demonstrate that aphrodisin already occurs in vaginal discharge before the female animals reach fertility. These findings may lead to the identificat ion of as yet unknown aphrodisin functions.