CORVALLIS, Ore. - University researchers have discovered one of the first pheromones in a vertebrate animal species that is produced by the male and helps him when courting a female, in this case making her more calm, receptive to mating and less apt to run away.

The study, to be reported Friday in the journal Science, was done with a species of terrestrial salamander called Plethodon jordani. But, as scientists learn more about this mysterious world of chemical communication, it seems likely that there may be many other pheromones that affect behavior and mating in many animal species, including humans.

"It's very unusual in nature to find a pheromone that male vertebrates use in courtship and mating," said Lynne Houck, an associate professor of zoology at Oregon State University and co-principal investigator on the study, along with colleagues at the University of Chicago and University of Louisville. "Usually you find these types of pheromones only in the female."

The researchers in this case identified the pheromone, a single protein component that affects the female, and the gene that is responsible for production of that protein. Of considerable interest, Houck said, is that this gene is similar, although not identical, to one found in humans.

In salamanders, the courtship and mating process is odd.

"Terrestrial salamanders aren't always wildly enthusiastic about mating, and there are only a few weeks or months of the year that the female will even consider the idea," Houck said. "And, during that time, the chances of her mating with a male are considerably reduced if he doesn't produce this particular pheromone."

In that process, one part of which is called a tail-straddling walk, the male deposits pheromones from a gland under his chin - a gland which only becomes active during mating times - onto the female's nose.

Repeated deposits of this chemical seem to soothe the female, m
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Contact: Lynne Houck
houckl@bcc.orst.edu
541-737-4353
Oregon State University
16-Sep-1999