【摘要】 来源于体外成熟和体外受精的牛早期胚胎与不同细胞的单层细胞共同培养，以检测不同阶段胚胎的细胞数。本研究共检测了３１５３枚桑椹胚和囊胚。通过体外培养４～１０ｄ，不同阶段的胚胎，早期桑椹胚、紧凑型桑椹胚、早期囊胚、囊胚、待扩展囊胚、扩展囊胚、待孵化囊胚和孵化囊胚，经检测其细胞数分别为：４５，６９，７０，８８，１０３，１２７，１３９和１５１。第９ｄ的囊胚细胞数比第７ｄ或第８ｄ的囊胚细胞数无显著差异，然而，不同等级的囊胚的细胞数差异显著（Ｐ＜０．０５）；同时，细胞数少的胚胎发育也慢。通过囊胚免疫法检测，第７ｄ、第８ｄ和第９ｄ回收的扩展囊胚的细胞数分别为６６，６０和５２。此外，虽然在子宫内膜细胞或输卵管细胞－子宫内膜细胞的单层细胞上的囊胚发育慢，且发育率低，但其细胞数与在其它单层细胞上发育的囊胚相比无显著差异。试验结果表明，通过体外化培养出来的囊胚细胞数也能达到体内囊胚的水平。更多还原

【Abstract】 Early bovine embryos (2-8 cells) derived from in vitro maturation and fertilization of oocytes were co-cultured with different somatic cells for evaluation of the number of nuclei at different developmental stages. By 4￣10 days of culture, the mean number of nuclei recorded for early morulae, late morulae, early blastocysts, blastocysts,expanding blastocysts, expanded blastocysts, hatching blastocysts and hatched blastocysts were 45, 69, 70, 88, 103, 127, 139 and 151, respectively. In co-culture with granulosa cells, the mean cell number (±s. e.) in different stage blastocysts recovered at D7 after insemination was similar to that in the corresponding stage blastocysts recovered at D8 or D9. However,a larger variation in cell numbers was evident among different grade D9 blastocysts than in D7 or D8 blastocysts (P<0. 05). Cell numbers in poor or fair blasto cysts lagged behind those in excellent or good ones (P<0. 05). By 7 days after insemina tion, average cell numbers in early BL, BL, expanding/expanded (ICM cells) BL were 78,98,66,respectively, by 8 days after insemination,the mean cell numbers in early BL,BL and expanding/expanded (ICM cells) BL were 73, 92, 60,respectively, while by 9 days after insemination, the mean cell numbers in early BL,BL and expanding/ expanded (ICM cells) BL were 70, 85, 52, respectively. Furthermore,in the co-culture with different somatic cells,embryos contained relatively similar numbers of nuclei, although those em bryos on U and OU monolayers developed considerably later or/and to a low rate. The results demonstrate that co-culture of early embryos with different somatic cells can result in numbers of nuclei comparable to those in in vivo blastocysts. Data show existence of a variation in cell numbers in different grades of blastocysts.更多还原