Oogenesis in Fundulus heteroclitus. I. Preliminary observations on oocyte maturation in vivo and in vitro
- Oak Ridge National Lab., TN
During the breeding season, the ovary of Fundulus heteroclitus contains follicles of all sizes up to around 1.8 mm in diameter and continuously ovulates eggs (1.7 mm) into the ovarian lumen. Vitellogenic follicles appear to extend up to 1.3 mm, while those larger than 1.4 mm are undergoing hydration concomitant with maturation. If feeding ceases, vitellogenesis appears to stop and maturational stages flush out of the ovary. Refeeding causes reappearance of maturational stages. A culture procedure was developed for dissected F. heteroclitus follicles, and a size range (1.3 to 1.4 mm) was defined which responded to added hormones by undergoing the same maturational changes (germinal vesicle breakdown, fusion, and peripheral detachment of oil droplets, appearance of activability) as occurs in vivo, although the extent of hydration was not quite as extensive. Ovulation, however, did not consistently occur in vitro. Both 11-deoxycorticosterone and progesterone are potent inducers of maturation in vitro, with median effective doses being 10 to 20 ng/ml. Hydrocortisone is about one-tenth as active. Human chorionic gonadotropin promotes maturational changes in about 25% of the follicles over a broad concentration range (1 to 100 IU/ml). The environmental and hormonal mechanisms which influence oocyte maturation in teleosts are discussed in relation to our findings for F. heteroclitus.
- OSTI ID:
- 6393156
- Journal Information:
- Dev. Biol.; (United States), Journal Name: Dev. Biol.; (United States) Vol. 62; ISSN DEBIA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Physiological aspects of oogenesis in two species of sticklebacks, Gasterosteus aculeatus L. and Apeltes quadracus (Mitchill)
The reproductive activity of Fundulus heteroclitus females from Woods Hole, Massachusetts, as compared with more southern locations