TRANSGENIC BOVINE CHIMERIC OFFSPRING PRODUCED FROM SOMATIC CELL-DERIVED STEM-LIKE CELLS

We have developed a method, using nuclear transplantation, to produce transgenic embryonic stem (ES)-like cells from fetal bovine fibroblast s. These cells, when reintroduced into preimplantation embryos, differ entiated into derivatives from the three embryonic germ layers, ectode rm, mesoderm, and endoderm, in 5-month-old animals. Six out of seven ( 86%) carves born were found to be chimeric for at least one tissue. Th ese experiments demonstrate that somatic cells can be genetically modi fied and then dedifferentiated by nuclear transfer into ES-like cells, opening the possibility of using them in differentiation studies and human cell therapy.