GDNF-Regulated Gene Expression in Cultures of Rat Spermatogonial Stem Cells

Expression of GDNF-regulated genes was studied in cultures of self-renewing rat spermatogonial stem cells established from 8-10 day old rat pups maintained in a defined serum free medium. GDNF is the primary regulator of spermatogonial stem cell self renewal in the rat. GDNF regulated genes were identified using microarray profiling rat spermatogonial stem cells in the presence and absence of GDNF. Highly enriched population of rat spermatogonial stem cells were maintained in defined serum free media which allowed for their continued self-renewal in the presence of GDNF. GDNF was withdrawn from cultures for 18 hours followed by replacement for 2, 4, and 8 hours. Gene expression was studied using microarray profiling prior to GDNF withdrawal, after GDNF withdrawal, and after 2, 4, and 8 hours of GDNF replacement. 3 replicate samples from each timepoint were analyzed.