title: Effects of retinol on the in vitro development of Bos indicus embryos to blastocysts in two different culture systems.
abstract: The objective of this study was to evaluate the effect of retinol on the in vitro development of early embryos of cultured Bos indicus (Expt 1) to the blastocyst stage in medium simplex of optimization (KSOM) or sintetic fluid of oviduct (SOF) or co-cultured (Expt 2) with an oviduct cell monolayer (OCM) in KSOM or SOF. A total of 3149 cumulus-oocyte complexes obtained by aspirating follicles (2-5 mm diameter) from ovaries of slaughtered animals were selected for IVM and incubated in TCM 199 supplemented with 25 mM HEPES at 39 degrees C in air with 5% CO(2) and maximum humidity for 24 h. In vitro fertilization (IVF) was performed in modified defined medium (mDM) medium. Eighteen hours after IVF, cumulus cells were removed and presumptive zygotes were randomly allocated to the experimental groups. Zygotes cultured (Expt 1) in KSOM + retinol, KSOM, SOF + retinol and SOF were incubated in maximum humidity at 39 degrees C, 5% CO(2), 5% O(2) and 90% N(2). Zygotes co-cultured (Expt 2) in KSOM + retinol + OCM, KSOM + OCM, SOF + retinol + OCM and SOF + OCM were incubated at 39 degrees C, 5% CO(2). In both experiments media were partially changed 48 h after IVF and unfertilized ova were removed. Afterwards embryos were kept in culture or co-culture for further 9 days. In Expt 1, blastocyst rates (day 7) were 14.6% (KSOM + retinol), 15.8% (KSOM), 16.4% (SOF + retinol) and 15.9% (SOF). In Expt 2, the blastocyst rates (day 7) were 25.4% (KSOM + retinol + OCM) 14.2% (KSOM + OCM), 24.3% (SOF + retinol + OCM) and 15.9% (SOF + OCM). The same influence profile of retinol was observed in the formation of the expanded (day 9) and hatched (day 11) blastocysts. The results obtained in Expt 2 demonstrated that the addition of 0.28 microg/ml retinol to the embryo culture media used in this study had a significant (p < 0.05) positive effect on bovine early embryonic development, under the conditions tested, and can be used to enhance in vitro embryo production.
authors.affiliation: Departamento de Medicina Veterinária/UFRPE, Av. D. Manoel de Medeiros s/n, Dois Irmãos, Recife-PE, Brazil.
authors.forename: P F
authors.initials: PF
authors.lastname: Lima
authors.forename: M A L
authors.initials: MA
authors.lastname: Oliveira
authors.forename: P B D
authors.initials: PB
authors.lastname: Gonçalves
authors.forename: M M
authors.initials: MM
authors.lastname: Montagner
authors.forename: H-D
authors.initials: HD
authors.lastname: Reichenbach
authors.forename: M
authors.initials: M
authors.lastname: Weppert
authors.forename: C C C
authors.initials: CC
authors.lastname: Neto
authors.forename: V M R
authors.initials: VM
authors.lastname: Pina
authors.forename: M H B
authors.initials: MH
authors.lastname: Santos
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000502:physiology*; D001826:Body Fluids; D002417:Cattle / Q000196:embryology*; D002455:Cell Division; D018920:Coculture Techniques / Q000662:veterinary; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods / Q000662:veterinary*; D047108:Embryonic Development / Q000187:drug effects* / Q000502:physiology; D005260:Female; D014801:Vitamin A / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D014801:Vitamin A