ISSN:
0148-7280
Keywords:
oocyte
;
meiotic competence
;
estrogen
;
PMSG
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Oocytes were removed from the follicles of rats at 15 to 31 days of age, and their ability to resume meiosis (“meiotic competence”) in vitro was correlated with their diameter and the stage of follicular development. The majority of oocytes explanted on day 15 did not resume meiosis when placed in culture, but the percentage of competent oocytes increased from 14.1% ± 3.0% on day 20 to 67.6% ± 3.3% on day 26 of age. This ability to resume maturation correlated well (r = 0.98) with the increase in diameter of oocytes and coincided with the development of antral follicles.Hypophysectomy on day 15 of age, but not on day 20, reduced the percentage (P 〈 0.001) and number (P 〈 0.001) of competent oocytes and was accompanied by a reduction in diameter of oocytes. Treatment with PMSG or E2 increased the number (P 〈 0.001) and percentage (P 〈 0.001) of competent oocytes. These results suggest that the ability of oocytes to mature in vitro is dependent upon stimulation by gonadotropins and that this action of gonadotropin may be mediated by production of estrogen within the follicles.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1120040509
