[Effect on development in NT embryos after transplantation of nuclei derived from transfected goat fetal fibroblasts suffering different treatments into enucleate eggs].

In order to improve the development rate of preimplantation nuclear transfer embryos (NT embryos) after transplanting nuclei derived from transgenic goat fetal cells, the donor fetal fibroblasts starved for 5 days in DMEM containing 0.5% FCS were divided into three groups and treated with different methods respectively before using as donor cell. Group 1 was frozen at -80 degrees C or in liquid nitrogen for several days or months. Group 2 was at first treated as the same as group 1, then cultured for 2-5 days in DMEM containing 10% FCS and starved for another 5 days subsequently. Group 3 was cultured for 2-5 days in DMEM containing 10% FCS and starved for another 5 days subsequently. The rate of G0/G1 phase cells from group 2 was 95.68% and significantly different from group 1's 88.66%. The rate of survival cells from group 2 was 99.9% and significantly different from group 1's 80.00% (P < 0.05).The morula- blastocyst stage NT embryos development rate of group 2 was 66.09% and significantly different from group 1's 22.00% and group 3's 50.51% (P < 0.05). All NT embryos of above three groups were transferred into synchronous oestrus recipients and the pregnant status of recipients was checked by B-mode ultrasound diagnosis after 35 days. The recipient pregnancy rate of group 2 was 45.83%, much higher than that of group 1(20.00%) and group 3 (29.58%). The result of this experiment showed that donor cells treated with freezing and two times starvation could significantly improve the rate of G0/G1 phase cells, the rate of survival cells, the NT embryos development rate and the recipient pregnancy rate.