Literaturdatenbank
Literaturdatenbank |
|
 |
|
Jones, S. M. (2011). Chapter 4 - hormonal regulation of ovarian function in reptiles. In D. Norris & K. Lopez (Eds.), Hormones and Reproduction of Vertebrates Vol. 3 - Reptiles, (pp. 89–115). San Diego: Elsevier.
Added by: Sarina Wunderlich (25 Jun 2011 12:41:40 UTC) |
| Resource type: Book Article DOI: 10.1016/B978-0-12-374930-7.10004-4 BibTeX citation key: Jones2011 View all bibliographic details  |
Categories: General Keywords: Echsen = saurians, Fortpflanzung = reproduction, Panzerechsen = crocodilia, Physiologie = physiology, Schildkröten = turtles + tortoises, Schlangen = snakes Creators: Jones, Lopez, Norris Publisher: Elsevier (San Diego) Collection: Hormones and Reproduction of Vertebrates |
Views: 6/767
Views index: 16% Popularity index: 4% |
| Abstract |
|
The reptilian ovary has two primary functions: the production of gametes and the secretion of hormones. Ovarian differentiation begins during embryonic development and, in many species, primordial follicles are present in the ovary by the time of hatching. The ovary produces steroid hormones (estrogens, androgens, and progestins) that circulate in association with plasma-binding proteins and bind to three complementary classes of specific tissue receptors. Metabolism of the primary steroids by peripheral tissues may involve either derivatization or conjugation. Ovarian activity is regulated via the hypothalamo–pituitary–gonadal (HPG) axis. Follicular maturation typically involves the deposition of large amounts of yolk during vitellogenesis, which is stimulated by estrogens secreted by the granulosa cells. In both oviparous and viviparous reptiles, the postovulatory follicles are transformed into secretory corpora lutea, which produce progesterone for species-specific periods. Luteolysis is stimulated by prostaglandins. Further research is particularly required into non-steroidal hormones produced by, or influencing, the reptilian ovary.
Added by: Sarina Wunderlich |