The image shows a developing Drosophila spermatid immunostained for caspase activity (green). TRITC-phalloidin is used to label actin (red). Caspase is required in spermiogenesis for the elimination of unwanted organelles and cytoplasm via apoptosis.
Biological Process: Spermatogenesis
See E. Arama et al. 2003 Caspase activity and a specific cytochrome C are required for sperm differentiation in Drosophila. Dev. Cell 4:687-697.
Author: Hermann Steller
Source: The Cell: An Image Library