Molecular Evidence (IMAGE) Cincinnati Children's Hospital Medical Center Caption This confocal microscopic image of an 8-day-old mouse's testicular section shows evidence of the PRC1 subcomponent Sall 4 (in green). Scientists report in Genes & Development finding that PRC1 is the key molecular and genetic switch that activates production of healthy male sperm, an important clue to understanding the causes of male infertility or congenital illness. Credit Cincinnati Children's Usage Restrictions Must credit Cincinnati Children's 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.