Open AccessAbortive expansion of the cumulus and impaired fertility in mice lacking the prostaglandin E receptor subtype EP 2
Author(s) -
Hiroko Hizaki,
Eri Segi,
Yukihiko Sugimoto,
Masahiro Hirose,
Tomomi Saji,
Fumitaka Ushikubi,
Toshifumi Matsuoka,
Yoichi Noda,
Takashi Tanaka,
Nobuaki Yoshida,
Shuh Narumiya,
Atsushi Ichikawa
Publication year - 1999
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.96.18.10501
Subject(s) - medicine , endocrinology , ovulation , human fertilization , biology , receptor , oviduct , andrology , gonadotropin , prostaglandin , ovarian follicle , chemistry , ovary , hormone , anatomy
Female mice lacking the gene encoding the prostaglandin (PG) E2 receptor subtype EP2 (EP2 −/− ) become pregnant and deliver their pups at term, but with a much reduced litter size. A decrease in ovulation number and a much reduced fertilization rate were observed in EP2 −/− females without difference of the uterus to support implantation of wild-type embryos. Treatment with gonadotropins induced EP2 mRNA expression in the cumulus cells of ovarian follicles of wild-type mice. The immature cumuli oophori from wild-type mice expandedin vitro in response to both follicle-stimulating hormone and PGE2 , but the response to PGE2 was absent in those from EP2 −/− mice. Cumulus expansion proceeded normally in preovulatory follicles but became abortive in a number of ovulated complexes in EP2 −/− mice, indicating that EP2 is involved in cumulus expansion in the oviductin vivo . No difference in the fertilization rate between wild-type and EP2 −/− mice was found inin vitro studies using cumulus-free oocytes. These results indicate that PGE2 cooperates with gonadotropin to complete cumulus expansion for successful fertilization.