title: Developmental capacity of mouse oocytes matured in vitro: effects of gonadotrophic stimulation, follicular origin and oocyte size.
abstract: Development of mammalian oocytes is usually correlated with ovarian follicular development. This correlation was tested by determining whether gonadotrophic stimulation of follicular development in immature mice resulted in a coordinated increase in the embryonic developmental capacity of the oocytes. Oocyte cumulus cell complexes were isolated at the germinal vesicle stage from small, medium and large antral follicles of 26-day-old mice and matured and fertilized in vitro. The frequency with which embryos from oocytes from small follicles completed the two-cell to blastocyst transition was lower than for embryos from oocytes from large follicles (33% and 79%, respectively). Germinal-vesicle stage oocyte-cumulus cell complexes were isolated from 22-26-day-old mice that were unprimed or primed by injection of equine chorionic gonadotrophin 48 h before isolation. Oocytes were matured in control medium, or in medium containing 1 microgram follicle-stimulating hormone (FSH) ml-1, and then fertilized in vitro. Priming did not increase the number of embryos completing the two-cell stage to blastocyst transition in the 22-day-old group nor did FSH treatment of maturing oocytes when the oocytes were isolated from unprimed 22-day-old mice. In contrast, priming increased the percentage of embryos completing the two-cell stage to blastocyst transition in the 26-day-old group by 20%. FSH treatment of maturing oocytes from the unprimed, 26-day-old group increased the number of embryos completing the transition to the same level as those in the primed 26-day-old group, but FSH did not increase the frequency of transition in the primed 26-day-old group.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Jackson Laboratory, Bar Harbor, Maine 04609.
authors.forename: J J
authors.initials: JJ
authors.lastname: Eppig
authors.forename: A C
authors.initials: AC
authors.lastname: Schroeder
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Brien
mesh_terms: D000367:Age Factors; D000818:Animals; D002478:Cells, Cultured; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005640:Follicle Stimulating Hormone / Q000494:pharmacology / Q000502:physiology*; D006064:Gonadotropins, Equine / Q000494:pharmacology; D051379:Mice; D009865:Oocytes / Q000166:cytology / Q000254:growth & development*; D006080:Ovarian Follicle / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy
chemical_list: D006064:Gonadotropins, Equine; D005640:Follicle Stimulating Hormone