Spermatogonial stem cell renewal in the mouse as revealed by sup3sup 3H- thymidine labeling and irradiation

Procedures are described for sectioning and staining mouse testes, x- irradiation of mice, and classification of developing sperm cells. Tables are presented to show frequency of labeled cells following exposure to various doses of x radiation. A discussion is presented of types of spermatogonia surviving various radiation doses and times of incorporation of $sup 3$H-TdR in the cycle of the seminiferous epithelium. Models of stem cell renewal systems are described. (HLW