Fig. 2 (IMAGE) Osaka University Caption The function of mouse NELL2 Left, 1, Germ cells produce NELL2 during spermatogenesis; 2, In response to NELL2 coming from testis, the sperm maturation machinery turns on in the epididymis; 3, Sperm obtain fertilizing ability during when they migrate through epididymis. Right, In the absence of NELL2, sperm are still generated in the testis but sperm maturation does not occur in the epididymis and males become infertile. Credit Osaka University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.