Tip of a Drosophila Testis (image) Institute for Research in Biomedicine (IRB Barcelona) Share Print E-Mail Caption In red, BigH1 expressed in germ stem cells and spermatocytes. In blue, the cell nuclei. Credit Albert Carbonell, IRB Barcelona. Usage Restrictions Citation Share Print E-Mail 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.