ERTL, C and WROBEL, KH (1992) ULTRASTRUCTURE AND MORPHOMETRY OF PREPUBERAL POSTNATAL GERM-CELL DEVELOPMENT IN THE BOVINE TESTIS. REPRODUCTION IN DOMESTIC ANIMALS, 27 (2). pp. 73-84. ISSN 0936-6768,
Full text not available from this repository.Abstract
The development of the male bovine postnatal prepuberal germ cell population was studied by electron-microscopical and morphometric means. Contrary to previous studies our investigation disclosed the existence of merely one postnatal germ cell type prior to onset of spermatogenesis, the prespermatogonium. Prespermatogonia are large, mostly round cells with a likewise large, spherical, electron-lucid nucleus, containing one to three characteristic nucleoli. Nuclear diameter amounts to approximately 10.4-mu-m, cellular volume to between 1800 and 2 200-mu-m3. The nucleus occupies 25 to 30 % of the cell, the mitochondrial fraction about 3.5 %. Prespermatogonia represent about 19% of the tubular volume in the four-week-old animal, this figure drops to about 3.5% in week 20 and rises again to about 11 % during the following proliferation period which lasts until week 25. The calculated absolute number of prespermatogonia in both testes is relatively constant through week 20 (between 0.44 and 0.65 x 10(9)) and increases sharply during the next five weeks to reach 2.4 x 10(9). The total length of all seminiferous tubules in one animal measures about 2 000 m in the four-week-old calf and about 10 000 m in the adult bull.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RABBIT TESTIS; SERTOLI CELLS; DIFFERENTIATION; BOVINE; TESTIS; PRESPERMATOGONIA; ULTRASTRUCTURE; MORPHOMETRY |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:44 |
| URI: | https://pred.uni-regensburg.de/id/eprint/54594 |
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