Makoto Nagano, PhD, DVM

Spermatogenesis is a process that produces numerous sperm everyday throughout life. This remarkably robust process is possible because it is supported by sperm-producing stem cells, called spermatogonial stem cells (SSCs), in the testis. Our investigations are directed to two areas of SSC research: to understand biology of SSCs and to clinically apply SSCs for male fertility preservation and restoration. In biological studies, we investigate how SSCs determine their fate, either to remain as stem cells or to produce differentiating cells that ultimately become sperm. For clinical SSC application, we envision that SSCs will be an important resource to restore fertility in boys and men. We are developing methods to isolate SSCs from the testis, amplify in a culture dish, freeze-store, and transplant back into the testis. These techniques should be effective particularly for boys who need to undergo chemotherapy, which is toxic to the testis, but cannot benefit from sperm-banking.