Bioquímica e Fisiologia: Acesso Aberto

Abstrato

The Induction of Pregnancy Block in Mice by Bodily Fluids via the Vomeronasal Organ

Roger N Thompson, Murtada Taha, Audrey Napier and Kennedy S Wekesa

Animals have evolved specific communication systems to identify and attract mates, and to discern the social status of conspecifics. In mice, these exchanges of information involve the emission and detection of pheromones. These pheromones are detected by the vomeronasal system. While urine has long been identified as the primary source of pheromones, including those responsible for pregnancy block, recent evidence indicates that there are other sources. These sources contain MHC class I peptides from the immune system and ESP1 from an exocrine gland. The MHC class I peptides have been identified as compounds that elicit the pregnancy block effect via the vomeronasal system, similar to the effect elicited by urine from male mice, including castrated or juvenile males. Here we provide evidence which shows bodily fluids such as saliva, blood serum or fecal extract, along with tissue extracts are capable of inducing the pregnancy block (Bruce Effect) paradigm, in a manner equivalent to female mice exposed to whole urine. While there appears to be a number of sources that can induce pregnancy block, one exception is the nervous system. Therefore, we conclude that pregnancy block can be mediated by stimuli from several different sources in the same manner as whole male urine.