title: Developmental block and programmed cell death in Bos indicus embryos: effects of protein supplementation source and developmental kinetics.
abstract: The aims of this study were to determine if the protein source of the medium influences zebu embryo development and if developmental kinetics, developmental block and programmed cell death are related. The culture medium was supplemented with either fetal calf serum or bovine serum albumin. The embryos were classified as Fast (n = 1,235) or Slow (n = 485) based on the time required to reach the fourth cell cycle (48 h and 90 h post insemination - hpi -, respectively). The Slow group was further separated into two groups: those presenting exactly 4 cells at 48 hpi (Slow/4 cells) and those that reached the fourth cell cycle at 90 hpi (Slow). Blastocyst quality, DNA fragmentation, mitochondrial membrane potential and signs of apoptosis or necrosis were evaluated. The Slow group had higher incidence of developmental block than the Fast group. The embryos supplemented with fetal calf serum had lower quality. DNA fragmentation and mitochondrial membrane potential were absent in embryos at 48 hpi but present at 90 hpi. Early signs of apoptosis were more frequent in the Slow and Slow/4 cell groups than in the Fast group. We concluded that fetal calf serum reduces blastocyst development and quality, but the mechanism appears to be independent of DNA fragmentation. The apoptotic cells detected at 48 hpi reveal a possible mechanism of programmed cell death activation prior to genome activation. The apoptotic cells observed in the slow-developing embryos suggested a relationship between programmed cell death and embryonic developmental kinetics in zebu in vitro-produced embryos.
authors.affiliation: São Paulo University (USP), Faculdade de Zootecnia e Engenharia de Alimentos, Pirassununga, SP, Brazil.
authors.forename: Sheila Merlo
authors.initials: SM
authors.lastname: Garcia
authors.affiliation: State University of Londrina (UEL), Laboratório de Reprodução Animal, DCV, CCA, Londrina, PR, Brazil.
authors.forename: Luciana Simões Rafagnin
authors.initials: LS
authors.lastname: Marinho
authors.affiliation: State University of Londrina (UEL), Laboratório de Reprodução Animal, DCV, CCA, Londrina, PR, Brazil.
authors.forename: Paula Alvares
authors.initials: PA
authors.lastname: Lunardelli
authors.affiliation: State University of Londrina (UEL), Laboratório de Reprodução Animal, DCV, CCA, Londrina, PR, Brazil.
authors.forename: Marcelo Marcondes
authors.initials: MM
authors.lastname: Seneda
authors.affiliation: São Paulo University (USP), Faculdade de Zootecnia e Engenharia de Alimentos, Pirassununga, SP, Brazil.
authors.forename: Flávio Vieira
authors.initials: FV
authors.lastname: Meirelles
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology* / Q000187:drug effects; D002417:Cattle / Q000196:embryology* / Q000378:metabolism; D016923:Cell Death; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology*; D053938:DNA Fragmentation / Q000187:drug effects; D046149:Embryo Culture Techniques / Q000379:methods*; D004622:Embryo, Mammalian / Q000187:drug effects; D005260:Female; D005307:Fertilization in Vitro; D059471:In Vitro Oocyte Maturation Techniques; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects
chemical_list: D003470:Culture Media