Hens may select sperm for healthier offspring

Female red junglefowl , the wild ancestor of the domestic chicken, may be able to optimise the immunity of their offspring by selecting sperm after mating with different males. That's the conclusion from a study led by Oxford University researchers published in this week's PNAS. 'In natural populations, males can coerce females and selecting sperm after mating with multiple males is a safer way to control offspring paternity for a hen,' explains Dr Tom Pizzari of Oxford University's Department of Zoology, one of the research team. Whilst previous work has demonstrated that hens are able to select against the sperm of related males after mating, quite what triggers this response is a mystery. The team focused their efforts on the Major Histocompatibility Complex ( MHC ), a gene complex that plays a key role in immune responses. 'Similarity at the MHC between two individuals is often a good proxy for their overall relatedness,' Tom tells me. In the study the team looked for evidence of sperm selection after both natural matings and artificial insemination.