In an interesting twist, the researchers found that the escort molecules belong to a family of proteins, called the major histocompatibility complex (MHC), which plays an important role in the immune system. The researchers speculate that in addition to being escort molecules, the MHC proteins might actively modulate an animal's response to pheromones. Modulation of pheromone activity might aid in the recognition of other animals.

The studies in mice add "a novel and unexpected layer of complexity to the process of pheromone detection," the researchers wrote in an article published in the March 7, 2003, issue of the journal Cell. The article was published online on March 4, 2003. The findings also suggest that, similarly, escort molecules, although of a different kind, may be important in smell and taste receptors.

HHMI investigators Catherine Dulac at Harvard University and Kirsten Fischer Lindahl at the University of Texas Southwestern Medical Center led the research teams that collaborated on the studies.

The pheromone communication system, which is found in a wide range of mammals, involves detection of chemical odorants released by animals. Detection of pheromones takes place in a specialized structure, called the vomeronasal organ (VNO). Although the VNO resides in the nasal cavity, the pheromone sensory system is distinct from the sense of smell, as are the chemical receptors involved. In animals possessing a pheromone sensory system -- including mice, dogs, cats and elephants -- the system governs a range of genetically preprogrammed mating, socia
'"/>

Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute
6-Mar-2003