DURHAM, N.C., Dec. 10 (UPI) -- U.S. scientists say they have discovered why the same sex-related odor receptors in humans and other primates are used in different ways.
Duke University Medical School researchers said the odor receptors work differently in each species due to genetic evolution and the resulting varying sensitivity to sex-steroid odors might play a role in mate selection and perhaps even help prevent cross-species couplings.
The researchers analyzed the sequences and functions of the gene for the odorant receptor OR7D4 in terms of perceiving two steroid molecules related to testosterone, androstenone and androstadienone. The study did not try to examine how the receptors and odor perception might relate to behavior.
"There's variation in sensitivity of the odorant receptor from this gene (all primates) have," said Associate Professor Hiroaki Matsunami, who led the research. "Maybe these molecules operate in the process of reproduction. The fact that there is variation fits with this theory. Reproduction demands an animal avoid attraction to other species, so variation in the receptor's sensitivity to these odors may prevent any cross-species attraction."
Matsunami said the research will ultimately focus on discerning how such odor perception might affect human social and sexual behavior.
The study that included Hanyi Zhuang and Ming-Shan Chien appears in the online, early edition of the Proceedings of the National Academy of Sciences.
