By Susan Milius
How much male company a female mouse sniffs and sees as she grows up affects how easy her eggs will be for sperm to fertilize.
Female house mice reared amid plenty of male mice in a lab mature to produce eggs that are relatively challenging to fertilize, says Renée Firman of the University of Western Australia in Crawley. Meanwhile, eggs from mice raised in all-female groups accept sperm for fertilization almost twice as readily, Firman and Western Australia colleague Leigh W. Simmons report October 16 in Proceedings of the Royal Society B.