Shedding light on male infertility

The underlying causes of male infertility are diverse; however, in almost 50% of the cases, there is no apparent reason for the infertility – it is idiopathic. Recently, one of the key players for sperm development, a new protein called CRIS, has been identified. CRIS knock-out males did not produce any sperm – they were infertile. However, some of the males had sperm, but their swimming behavior was completely different from normal sperm, resulting in a severely reduced fertility.