Effects of donor cells on in vitro development of cloned bovine embryos

The donor cells from different individuals and with different foreign genes introduced were investigated to determine their effects on the efficiency of somatic cell nuclear transfer （SCNT）. The bovine ear fibroblast from different individuals was isolated, cultured, and then transfected with foreign genes to establish the stable cell lines, which were used as donor cells for nuclear transfer. The oocytes were obtained through ovum pick up operation. After in vitro maturation, the M II phase oocytes were selected as receptors for nuclear transfer. The reconstructed embryos were cultured in vitro and observed at 2 h, 48 h, and 7 days after transfer to assess the rate of fusion using cleaved and blastocyst as the parameters of SCNT efficiency. The donor cells from different individuals （04036, 06081, 06088, and 06129） had no obvious effect on the fusion and cleaved rate, whereas there was significant difference in the blastocyst rate （P〈0.05）, and the rate was 62.3%, 37.0%, 35.1%, and 15.6%, respectively. There was no significant difference among the rate of fusion, cleaved and blastocyst in donor cells with different foreign genes （P〉0.05）. It was concluded that the genetic background of the donor cells could affect the efficiency of SCNT, while the introduction of foreign genes into the donor cells had no obvious effect on the efficiency. This study provides useful information for the SCNT and would benefit in promoting the efficiency.