<i>In vivo</i> development ability of SCNT embryos derived from transgenic kidney epithelial cells.

a: Numbers in parentheses indicate the number of non-transgenic SCNT embryos transferred to support the pregnancy. b: Detection of fetal sac and/or fetus. c: The birth weight of the three piglets was considerably less than the average birth weight (500 g) of the Clawn miniature pig. Therefore, they might be premature and we could not save their life. d: We do not know the reason why four co-transfers of transgenic SCNT embryos and non-transgenic ones produced no viable transgenic piglets whereas the one transfer of transgenic embryos by themselves produced viable piglets. One possible explanation may be as follows. We use around 200 embryos for one transfer, and when the number of transgenic embryos prepared during a certain period of time does not reach 200, we includeed non-transgenic ones. In the case when we could prepare more than 200 transgenic embryos, we did not include non-transgenic ones. In the latter case, their quality was good enough for pregnancy. In vivo development ability of SCNT embryos derived from transgenic kidney epithelial cells.