Antagonistic roles of Rac and Rho in organizing the germ cell microenvironment.

The capacity of stem cells to self renew and the ability of stem cell daughters to differentiate into highly specialized cells depend on external cues provided by their cellular microenvironments [1-3]. However, how microenvironments are shaped is poorly understood. In testes of Drosophila melanogaster, germ cells are enclosed by somatic support cells.