169 INFLUENCE OF TIME BEFORE BOS INDICUS OOCYTE ASPIRATION ON EMBRYO DEVELOPMENTAL COMPETENCE, EXPRESSION OF MATER AND OCT-4, AND FOLLICULAR STEROID CONCENTRATION
R. Urrego A B , E. Herrera B C , N. Chavarría A , O. Camargo D and N. Rodriguez-Osorio AA Grupo Centauro, Universidad de Antioquia, Medellín, Colombia;
B Grupo INCA-CES, Facultad de Medicina Veterinaria y Zootecnia, Universidad CES, Medellín, Colombia;
C Grupo Biología CES-EIA, Universidad CES, Medellín, Colombia;
D Grupo de Biotecnología Animal, Universidad Nacional de Colombia, Medellín, Colombia
Reproduction, Fertility and Development 26(1) 198-198 https://doi.org/10.1071/RDv26n1Ab169
Published: 5 December 2013
Abstract
The ability of bovine embryos to develop to the blastocyst stage, to implant, and to generate healthy offspring, depends greatly on the oocyte contribution. Oocyte competence is attributed to its close communication with the follicular environment and to its capacity to synthesise and store great amounts of mRNA. Higher developmental competence of bovine oocytes has been associated with the expression of certain genes and with the steroid concentration in the follicular fluid. Hence, the aim of this study was to establish the influence of OCT-4 and MATER mRNA abundance in the oocyte and the influence of progesterone and oestradiol follicular fluid concentration on the competence of bovine oocytes retrieved 30 min or 4 h after slaughter. Cumulus–oocyte complexes (COC) were left in postmortem ovaries for 30 min (Group I) or 4 h (Group II) at 30°C before aspiration. Progesterone and oestradiol concentrations were measured in the follicular fluid in both groups by immunoassay using an Immulite 2000 analyzer. Immature oocytes were evaluated for MATER and OCT-4 mRNA abundance by real-time PCR (total RNA isolated from pools of 100 oocytes per repeat) or were subjected to in vitro maturation (IVM), in vitro fertilization (IVF), and in vitro culture (IVC). For in vitro embryo production, 455 (Group I) and 470 (Group II) COC were used in three repeats. Progesterone concentration was lower (P ≤ 0.05) in Group II than in Group I. Conversely, oestradiol concentration did not vary between groups. Similarly, Group II oocytes exhibited the highest (P < 0.05) MATER and OCT-4 abundance. For embryo development, there were no significant differences between cleavage rates (72 h post-insemination) between both groups. However, blastocyst (168 h post-insemination) and hatching (216 h post-insemination) rates in Group II were greater (P < 0.05) with 21.3 compared with 30.7% and 54.2 compared with 75.3%, respectively. These results indicate that progesterone concentration in the follicle and the abundance of MATER and OCT-4 transcripts could be good predictors of embryo developmental competence and that retrieving COC 4 h after slaughter could increase blastocyst and hatching rates.
This work was supported by COLCIENCIAS COD 122852128473 Colombia.
