June 24, 2010

Mating Game More Complicated Than X And Y

A woman's body could be instinctively selective about sperm, allowing some sperm to make it to the egg while killing off the chances of less suitable contenders, an Australian researcher said Wednesday.

Professor Sarah Robertson, of the University of Adelaide, suggested that sperm contains "signaling molecules" that activate immunity changes in a woman's body so the sperm is accepted.

However, some apparently healthy sperm have failed to activate these changes, leading Prof. Robertson to suggest that the female system can be "choosy" about its biological mate. "It's rather like a two-way dance," she told AFP.

"The male provides information that increases the chances of conception and progression to pregnancy, but the female body has a quality control system which needs convincing that his sperm is compatible," Robertson said.

"That's where the dance can go wrong with some couples -- if the male signals are not strong enough, or if the female system is too "Ëœchoosy'," she explained.

Robertson suggested that sperm was more likely to fail if the woman had not been exposed to that man's semen for at least three months.

"We used to think that if a couple couldn't get pregnant, and the man's semen test was normal, the problem lay with the woman. But it appears this is not always the case," Robertson noted.

Further work and research is needed to potentially help improve treatments for infertility and miscarriages, according to researchers.


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