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

Sperm are male reproductive (sex) cells. The word "sperm" can refer to spermatozoon (singular) or spermatozoa (plural). Sperm are tiny cells with an oval-shaped body and a long tail. They measure just ...

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