关键词: 牛; 卵母细胞; 体外成熟; 亮甲酚蓝染色; 浓度; 葡萄糖-6-磷酸脱氢酶

Abstract: The aim of the present investigation was to study the effect of IVM of cow with different concentration brilliant cresyl blue (BCB) staining on the oocytes selection. For this purpose, Compact cumulus oocyte complexes (COCs) were recovered from slaughterhousecollected bovine ovaries and classified as control group, which were cultured immediately without exposure to BCB stain;treatment group were stained with different concentrations BCB(13,26,39 and 52 μmol/L BCB) for different time before culture. Treated oocytes were then classified according to their cytoplasm coloration: oocytes with a blue cytoplasm or grown oocytes(BCB+) and oocytes without a blue cytoplasm or growing oocytes(BCB-) . Oocytes were stained with different concentration BCB for different time before culture in this study. The result showed that:①The percentage of Colouring and mature for selected oocytes was different by treated with different concentrations BCB. The percentages of BCB+ oocytes obtained after staining with 26 μmol/L (27.7%),39 μmol/L (27.6%)and 52 μmol/L BCB (31.9%) were higher (P<0.05) than those obtained with 13 μmol/L(2.1%); ②BCB+ oocytes exhibited a higher (P<0.05) maturation rate (mean rate:77.4%;n=62)than BCB(51.3%;n=236) and control oocytes (60.2%;n=98);③There were no significant differences in the percentages of BCB+ oocytes reaching the MII stage among BCB concentrations;④There were no significant differences in nuclear maturation between control and BCB exposed oocytes (BCB+ plus BCB- ),independent of the BCB concentration;⑤After exposure different time BCB, the result showed that the percentage of BCB+ oocytes were different. The percentages of BCB+ oocytes obtained after staining with 26 μmol/L BCB for 90 min(75%) were a higher(P<0.05)than those oocytes obtained after staining with 26 μmol/L BCB for 60 min(57.14%) and 30 min(40%). These results show that the staining of cow cumulusoocyte complexes with BCB before in vitro maturation could be used to select developmentally competent oocytes.

Key words: cow; oocytes; IVM; brilliant cresyl blue; concentration; G6PDH