title: High-Yield Superovulation in Adult Mice by Anti-Inhibin Serum Treatment Combined with Estrous Cycle Synchronization.
abstract: Producing many mature oocytes is of great importance for assisted reproductive technologies. In mice, superovulation by consecutive injections of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) has been the gold standard for oocyte collection. However, the yield of mature oocytes by this regimen can fluctuate according to the stage of the estrous cycle, strain, and age. Therefore, our objective was to develop a high-yield superovulation protocol to collect higher numbers of oocytes from adult female mice of different strains and ages. First, we aimed to synchronize the estrous cycle using C57BL/6 (B6) female mice. Most (93%) were synchronized to metestrus after two daily injections of progesterone. Second, we found that with the injection of anti-inhibin serum (AIS) instead of eCG, the mean number of ovulated oocytes almost doubled (21 vs. 41 per mouse). Third, by combining estrous cycle synchronization with two AIS injections, we obtained 62 oocytes per mouse, about three times that with the eCG-hCG protocol. Importantly, this approach increased the proportion of mice that ovulated >25 oocytes from about 40% (eCG-hCG) to 90%. The same protocol was also effective in other inbred (BALB/cA), outbred (ICR), and hybrid (B6D2F1) strains. In addition, B6 female mice aged over 1 yr ovulated 1.8-fold more oocytes by this protocol. Thus, estrous cycle synchronization followed by AIS-hCG yielded a broadly applicable, highly efficient superovulation. This protocol should promote the effective use of invaluable female mouse strains and decrease the numbers of animals euthanized.
authors.affiliation: RIKEN BioResource Center, Tsukuba, Ibaraki, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Hasegawa
authors.affiliation: RIKEN BioResource Center, Tsukuba, Ibaraki, Japan jmochida@rtc.riken.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Mochida
authors.affiliation: RIKEN BioResource Center, Tsukuba, Ibaraki, Japan Laboratory of Animal Reproduction, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Inoue
authors.affiliation: Animal Facility, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Noda
authors.affiliation: Animal Facility, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Tamao
authors.initials: T
authors.lastname: Endo
authors.affiliation: Laboratory of Veterinary Physiology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
authors.affiliation: RIKEN BioResource Center, Tsukuba, Ibaraki, Japan Graduate School of Life and Environmental Science, University of Tsukuba, Ibaraki, Japan The Center for Disease Biology and Integrative Medicine, Faculty of Medicine, University of Tokyo, Tokyo, Japan ogura@rtc.riken.go.jp.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Ogura
mesh_terms: D000375:Aging; D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology*; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004973:Estrus Synchronization / Q000187:drug effects*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005640:Follicle Stimulating Hormone / Q000097:blood; D007265:Inhibins / Q000037:antagonists & inhibitors* / Q000276:immunology*; D008686:Metestrus / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D009865:Oocytes; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology; D013480:Superovulation / Q000187:drug effects*; D015044:Zona Pellucida / Q000187:drug effects
chemical_list: D019138:Antibodies, Blocking; D006063:Chorionic Gonadotropin; D011374:Progesterone; D007265:Inhibins; D005640:Follicle Stimulating Hormone
keywords: estrous cycle; in vitro fertilization; inhibin; mouse; superovulation