Increasing the Number of Transferred Embryos Results in Delivery of Viable Transgenically Cloned Guangxi Bama Mini-pigs

The somatic cell nuclear transfer (SCNT) technique is the most popular method for producing genetically modified pigs, but its efficiency depends upon a number of factors. In the present study, we attempted to generate transgenically cloned Guangxi Bama mini-pigs--which possess great potential for modeling human diseases--through genetic modification of fibroblasts, followed by SCNT and embryo transfer (ET). However, the first batch of five recipients transferred achieved a low number of cloned embryos (148.2 ± 13.0) and failed to become pregnant. We then changed the ET strategy (significantly increasing the number of transferred embryos [greater than 200, n = 7]), resulting in the delivery of three litters and a total of sixteen live-born cloned Guangxi Bama mini-pigs in which the integrated transgene was confirmed by genotyping. Thus, such a practical strategy can now be employed in our future work to create transgenic Guangxi Bama mini-pigs more efficiently.