Cyclic adenosine monophosphate modulator supplementation on in vitro maturation of bovine oocytes
Minu Xaviour, R.S. Abhilash, C. Jayakumar, Amritha Aravind and K. Raji
Study evaluated the role of cAMP modulator (Forskolin and 3-isobutyl-1- methyl xanthine) supplementation on developmental competence of bovine oocytes. Cumulus oocyte complexes recovered from bovine ovaries of unknown reproductive status were used for the study. Oocytes retrieved by aspiration method were graded based on cumulus cell distribution and culture grade oocytes were selected for the study. A total of 414 culture grade oocytes were taken and divided into two groups. Group I constituted of 201 oocytes in which pre-maturation was carried out for a period of 2 h. In group II, 213 oocytes were selected in which normal maturation was carried out. Maturation was assessed after 24h of culture in CO2 incubator maintained at 38.5o C in 95 per cent humidified atmosphere of 5 per cent CO2 . Fertilisation was carried out using frozen thawed semen and the presumptive zygotes were then transferred to culture media and cleavage was assessed 48 h after insemination. A significantly higher maturation rate (p ≤0.05) was observed in group I compared to group II (86.85 ± 1.19 vs 79.88 ± 2.67). There was a highly significant increase (p ≤0.01) in cleavage rate in group I (65.92 ± 1.23) compared to group II (59.29 ± 1.50). A higher fertilisation rate was observed in group I (75.35 ± 1.19) than group II (71.88 ± 2.56). It could be concluded that pre-maturation with cAMP modulators improved the developmental competence of bovine oocytes.
Keywords: Oocyte, pre-maturation, cAMP modulators, forskolin