S. Roh et Jt. Yoon, Production of HanWoo (Bos taurus coreanae) fetuses following interbreed somatic cell nuclear transfer, J VET MED S, 63(9), 2001, pp. 945-948
The possibility of producing HanWoo (Bos taurus coreanae) calves from trans
ferable bovine embryos, obtained by interbreed nuclear transfer using Holst
ein cytoplasts and surrogates, was investigated. As donor nuclei, HanWoo fe
tal fibroblasts were used. Cells were induced into quiescence by serum depr
ivation for 4-7 days before nuclear transfer. In vitro matured Holstein Ooc
ytes were enucleated, and single donor cell was placed into the perivitelli
ne space of enucleated oocyte. After reconstruction, the embryos were fused
, activated and cultured. On day 7, the embryos that developed to the blast
ocyst stages were transferred into Holstein recipient cows on day 6 to 7 of
estrous cycle (estrus=0). The reconstructed embryos were successfully fuse
d 58.8%; 47/80), cleaved (91.5%; 43/47), and developed to blastocysts (29.8
%; 14/47). Eleven blastocysts were transferred into 5 Holstein recipient co
ws. Two recipients were pregnant, confirmed by ultrasonography at day 60 of
gestation. But, one of them was opened between on day 80 to 100 of pregnan
cy, and the other bad a stillbirth on day 255. The stillborn calf was physi
cally normal, and we couldn't find any evidence of anomaly. These results s
how that cells derived from HanWoo somatic cell lines can be reprogrammed b
y interbreed nuclear transfer and develop subsequently in vivo as well as i
n vitro.