title: Evaluation of developmental competence of in vitro-produced porcine embryos based on the timing, pattern and evenness of the first cleavage and onset of the second cleavage.
abstract: The following selection markers for in vitro-produced porcine embryos were investigated: the timing, pattern and evenness of the first cleavage and the timing of the second cleavage. The embryos that cleaved by 30 h post-insemination (hpi) developed to blastocysts at a significantly higher rate (60.9%) and with a significantly higher cell number (33.6 cells) than those of embryos cleaved by 36 hpi (26.4% and 23.6 cells, respectively, P<0.05). Blastocyst proportions derived from 2- and 3-cell embryos cleaved by 30 hpi (68.2 and 65.3%, respectively) were significantly higher than those of 4- and >4-cell embryos (46.3 and 42.6%, respectively, P<0.05). The cell number per blastocyst generated from 2-cell embryos was significantly greater (37.3 cells) than those from 3-, 4- and >4-cell embryos (23.6-27.8 cells, P<0.05). Among embryos cleaved by 30 hpi, the blastocysts derived from evenly cleaved embryos (40.6 cells) were of significantly better quality than those derived from unevenly cleaved embryos (33.2 cells, P<0.05), although their blastocyst rates did not differ. The evenly cleaved embryos that underwent subsequent cleavage within 18 h had significantly higher blastocyst rates (72.7-81.0%) and quality (36.2-40.9 cells) than those without subsequent cleavage (48.3% and 22.5 cells, respectively, P<0.05) during the same period. In conclusion, the timing, pattern and evenness of the first cleavage and the timing of the second cleavage affected the developmental competence and quality of in vitro-produced porcine embryos.
authors.affiliation: Department of Animal Science, National Institute of Agrobiological Sciences, Ibaraki, Japan.
authors.forename: Thanh Quang
authors.initials: TQ
authors.lastname: Dang-Nguyen
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Tamas
authors.initials: T
authors.lastname: Somfai
authors.forename: Manabu
authors.initials: M
authors.lastname: Ozawa
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakai
authors.forename: Naoki
authors.initials: N
authors.lastname: Maedomari
authors.forename: Nguyen
authors.initials: N
authors.lastname: Viet-Linh
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kanai
authors.forename: Bui Xuan
authors.initials: BX
authors.lastname: Nguyen
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D001757:Blastomeres / Q000502:physiology*; D002452:Cell Count; D002970:Cleavage Stage, Ovum / Q000502:physiology*; D046149:Embryo Culture Techniques / Q000662:veterinary; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary; D007700:Kinetics; D008297:Male; D034421:Sus scrofa / Q000196:embryology*