Reproduction Abstracts

Until recently the mammalian oviducts or fallopian tubes were regarded as inert organs that provide a passive racecourse where spermatozoa compete against each other to reach the egg. Recent evidence suggests, however, that the female reproductive tract recognises the arrival of spermatozoa and initiates changes in gene expression and protein secretion profiles. We have observed that X- and Y-chromosome bearing spermatozoa alter gene expression in the maternal tract in different ways. This observation suggests that the female reproductive tract can sense the genetic characteristics of the spermatozoa. We hypothesise the existence of alternative scenarios: either the female reproductive tract is equipped with suitable sensory mechanisms, or the spermatozoa send out specific signals according to their genetic makeup to manipulate the maternal milieu for their own benefit. We need to develop tools with high precision to prove the validity of these hypotheses. However, one point is clear. Sperm transport in the female reproductive tract is not a simple race, where whoever runs faster wins the game and reaches the egg, as recently depicted in the popular media. It is a highly complex series of events. Understanding these interactions may help us learn the fundamental aspects of intercellular communication which induces short-term immune-tolerance.