For the first time, testicular tissue frozen before puberty was replanted and led to sperm production.

Sperm cells move through fluids that should stop them almost instantly, yet new research suggests they succeed by exploiting unusual properties of active living matter.

Paterna Biosciences says it has determined the set of instructions needed to turn sperm-making stem cells into "normal, mature" sperm.

Men who do not produce sperm can’t be helped by existing fertility treatments, but a start-up is now claiming it can grow ...

A San Francisco biotech start-up races sex cells on tiny tracks. Can an internet joke become a serious business?