ISSN:
1439-0264
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Three classes of spermatogonia were discerned: undifferentiated A spermatogonia (Ais, Apr, Aal), differentiated A spermatogonia (A1, A2) and differentiated B spermatogonia (B1, B2). Cell counts performed throughout the seminiferous epithelial cycle in the breeding season revealed that the number of undifferentiated A spermatogonia was lowest in the presence of differentiated A1 and A2 spermatogonia during stages I–II to III–IV. In the non-breeding season a highly significant increase in the number of undifferentiated spermatogonia occurred in an animal with moderate germ cell loss exclusively at stages I–II to III–IV, when the Ai and A2 spermatogonia degenerated. In three other animals involved in severe cell loss, enhanced proliferation of undifferentiated spermatogonia was much greater than in the animal mentioned above. These results suggest the presence of a feedback mechanism between undifferentiated and differentiated spermatogonia, which may be considered to play an important role in regulating seasonal changes in spermatogonial proliferation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1439-0264.1991.tb00751.x
