Open AccessSpermatogenesis in immature mammals
Author(s) -
HAMANO KOHICHI,
SUGIMOTO RYO,
TAKAHASHI HIROSHI,
TSUJII HIROTADA
Publication year - 2007
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1111/j.1447-0578.2007.00177.x
Subject(s) - spermatogenesis , biology , gonocyte , stem cell , germ cell , andrology , microbiology and biotechnology , transplantation , immunology , sertoli cell , medicine , endocrinology , gene , genetics
Mammalian spermatogenesis has been studied extensively as a prime theme of male reproductive biology, especially for germ cell production, fertilization and development. Investigation of spermatogenesis has provided us with the opportunity to both study the male germ line stem cells and generate the transgenic animals. Spermatogenesis is conducted in the seminiferous tubules, which end in the rete testis. The organization of spermatogenesis means that the spermatogonia are uniformly distributed around the seminiferous tubules. The pubertal establishment and mature maintenance of spermatogenesis requires precursor cells. In bull testes at 4 weeks postnatal, gonocyte migration occurs and differentiated spermatogonia are recognized after 8 weeks. Within the period of 4–8 weeks of age, spermatogonial stem cell conversion and niche formation must occur. Spermatogonial stem cells are the only cells that can undergo self‐renewal in spermatogenesis. Spermatogonial stem cell transplantation can potentially contribute to studies of gene expression during spermatogenesis and provide genetic progress in domestic animals. Bull spermatogonial stem cells have been demonstrated to be capable of colonizing recipient mouse seminiferous tubules. (Reprod Med Biol 2007; 6 : 139–149)