The mouse vomeronasal organ contains more than 300 different receptors, but only a few of them have been matched with the pheromones they detect. Pheromone-receptor pairs have been hard to identify because the body releases pheromones in only small quantities.
"In the past decade or so, studies in insects have identified pheromones, their receptors and even some neural pathways that control courtship," Yu says. "But in mammals we have known very little. Part of the reason is that we know next to nothing about what the mammalian pheromones are and which receptors recognize them."
In an attempt to find more pairs of pheromone receptors, Yu and his colleagues took tissue samples from the vomeronasal organ in mice, and then looked for cells that responded to the urine of female mice. With help from Stowers' state-of-the-art Lab Animal Services Facility and using resources from the Institute's Molecular Biology, Microscopy and Proteomics centers, the research team developed a novel approach using calcium imaging to analyze the cells and isolate the pheromone receptors.
"Since each vomeronasal neuron only expresses a single type of receptor, we were able to isolate the cells and figure out which receptors they express," Yu says. "With this approach we bypassed the need of knowing the pheromones to figure out the function of the receptors. We then used the receptors to figure out which urine fraction contains the active pheromones. So technically, we solved a problem that had frustrated the field for some time."
The researchers identified two previously unknown pheromone-receptor p
|Contact: Kim Bland|
Stowers Institute for Medical Research