title: Promising system for selecting healthy in vitro-fertilized embryos in cattle.
abstract: Conventionally, in vitro-fertilized (IVF) bovine embryos are morphologically evaluated at the time of embryo transfer to select those that are likely to establish a pregnancy. This method is, however, subjective and results in unreliable selection. Here we describe a novel selection system for IVF bovine blastocysts for transfer that traces the development of individual embryos with time-lapse cinematography in our developed microwell culture dish and analyzes embryonic metabolism. The system can noninvasively identify prognostic factors that reflect not only blastocyst qualities detected with histological, cytogenetic, and molecular analysis but also viability after transfer. By assessing a combination of identified prognostic factors--(i) timing of the first cleavage; (ii) number of blastomeres at the end of the first cleavage; (iii) presence or absence of multiple fragments at the end of the first cleavage; (iv) number of blastomeres at the onset of lag-phase, which results in temporary developmental arrest during the fourth or fifth cell cycle; and (v) oxygen consumption at the blastocyst stage--pregnancy success could be accurately predicted (78.9%). The conventional method or individual prognostic factors could not accurately predict pregnancy. No newborn calves showed neonatal overgrowth or death. Our results demonstrate that these five predictors and our system could provide objective and reliable selection of healthy IVF bovine embryos.
authors.affiliation: National Livestock Breeding Center, Nishigo, Fukushima, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sugimura
authors.forename: Tomonori
authors.initials: T
authors.lastname: Akai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hashiyada
authors.forename: Tamás
authors.initials: T
authors.lastname: Somfai
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Inaba
authors.forename: Muneyuki
authors.initials: M
authors.lastname: Hirayama
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Yamanouchi
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsuda
authors.forename: Shuji
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Aikawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Ohtake
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Konishi
authors.forename: Kei
authors.initials: K
authors.lastname: Imai
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology*; D001757:Blastomeres / Q000166:cytology; D002417:Cattle; D005260:Female; D005307:Fertilization in Vitro / Q000295:instrumentation* / Q000379:methods*; D011247:Pregnancy