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Low incubation temperature successfully supports the in vitro bovine oocyte maturation and subsequent development of embryos

2017; Asian-Australasian Association of Animal Production Societies; Volume: 31; Issue: 6 Linguagem: Inglês

10.5713/ajas.17.0569

1976-5517

Uğur Şen, Mehmet Kuran,

Tissue Engineering and Regenerative Medicine

Objective The aim of this study was to compare the effects of 36.5°C and 38.5°C incubation temperatures on the maturation of bovine oocytes and developmental competence of embryos. Methods In experiment 1, oocytes were maturated in bicarbonate-buffered TCM–199 for 22 hours in a humidified atmosphere of 5% CO2 in the air at either 36.5°C or 38.5°C and nuclear maturation status were determined. In experiment 2, in vitro fertilized oocytes were allocated randomly into synthetic oviductal fluid medium with or without a mixture of 1 mM L-glutathione reduced and 1,500 IU superoxide dismutase and cultured in a humidified atmosphere of 5% CO2, 5% O2, and 90% N2 in the air at 38.5°C for 8 days. Results There were no significant differences between incubation temperatures in terms of oocyte maturation parameters such as cumulus expansion, first polar body extrusion and nuclear maturation. Incubation temperatures during in vitro maturation had no effects on developmental competence of embryos, but supplementation of antioxidants increased (p< 0.05) developmental competence of the embryos. Blastocysts from oocytes matured at 38.5°C had comparatively higher inner cell mass, but low overall and trophectoderm cell numbers (p<0.05). Conclusion The results of present study showed that maturation of bovine oocytes at 36.5°C may provide a suitable thermal environment for nuclear maturation and subsequent embryo development. Keywords: Bovine; In vitro Maturation; Culture Temperatures; Antioxidants; Embryo Development