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Effects of gonadotropins upon the incidence and kinetics of meiotic maturation of macaque oocytes in vitro
Author(s) -
Schramm Ralph D.,
Tennier Michael T.,
Boatman Dorothy E.,
Bavister Barry D.
Publication year - 1994
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.1080370415
Subject(s) - germinal vesicle , endocrinology , biology , medicine , luteinizing hormone , follicle stimulating hormone , gonadotropin , ovulation , follicular phase , oocyte , andrology , hormone , embryo , microbiology and biotechnology
The specific aim of this study was to determine the effects of gonadotropins in vitro upon the incidence of and precise time interval to germinal vesicle breakdown (GVB) and extrusion of the first polar body (PB1) in oocytes from nonstimulated rhesus monkeys. Cumulus‐enclod germinal vesicle (GV) stage oocytes from 10 normal, cycling rhesus monkeys in the follicular phase of the menstrual cycle were cultured with either: (1) 1.0 μg/ml human follicle‐stimulating hormone (hFSH), (2) 10 μg/ml human luteinizing hormone (hLH), (3) 1.0 μg/ml hFSH and 10 μg/ml hLH, or (4) no gonadotropins (controls). Oocytes (n = 234) were examined at 3‐hr intervals from 0 to 21 hr and at 4‐hr intervals from 24 to 52 hr for GVB and PB1. Neither the incidence of GVB (hFSH: 63.5%; hLH: 56.1%; both gonadotropins: 63.1%; no gonadotropins: 53.6%) nor extrusion of PB1 (hFSH: 41.3%; hLH: 36.4%; both gonadotropins: 36.9%; no gonadotropins; 31.9%) differed ( P > 0.05) among treatments. The time to GVB was accelerated ( P < 0.05) by gonadotropins (hFSH: 10.8 ± 1.7 hr; hLH: 10.1 ± 1.8 hr; both gonadotropins: 8.8 ± 1.1 hr) when compared to controls (17.4 ± 2.0 hr). However, the time interval to extrusion of PB1 did not differ ( P > 0.05) among treatments (hFSH: 32.3 ± 1.2 hr; hLH: 35.1 ± 1.4 hr; both gonadotropins: 35.2 ± 1.3 hr; no gonadotropins: 34.1 ± 1.2 hr). The mean interval to extrusion of PB1 was 34.1 ± 0.6 hr. In conclusion, GVB and PB1 extrusions appear to be, in part, independently regulated events in macaque oocytes matured in vitro since the timing of PB1 extrusion is not tightly coupled with the onset of GVB. Although the developmental potential of oocytes may be enhanced by gonadotropins, alternative approaches must be developed to improve the poor competence of oocytes from nonstimulated monkeys to mature in vitro. © 1994 Wiley‐Liss, Inc.