second cattle cloning.
|In 1986, Neal
working at the University of Wisconsin, cloned
a cow from early
embryo cells. Though the race to clone
the first farm animal had already been won by Steen Willadsen in 1984, Prather, Eyestone, and First's
project was undertaken roughly at the same time as
The experiment, despite being a conducted as a research project at the Animal Science Lab of the University of Wisconsin, was funded by cattle company W.R. Grace and Company. W.R. Grace wanted a means to mass produce valuable cattle embryos. Each cloned embryo would be allowed to grow to eight cells, the blastocyst stage. Each of these cells would then be used to clone another cow, and so on, creating a large number of identical embryos.
Randal Prather was the doctoral student, who led the actual implementation of the project. The team began by fusing a single celled embryo to a fertilized egg cell whose nucleus had been removed. This was accomplished using an electrical current generated by a machine designed to fuse together cells. Next the fertilized egg was placed in a sheep oviduct and allowed to grow to the eight cell stage before being inserted into the uterus of a surrogate mother. Willard Eyestone borrowed Willadsen's idea of incubating the early embryo cells in a sheep oviduct, but Eyestone's process was different in that he extracted the oviducts from the sheep and kept them alive in the lab while the embryos were growing inside.
W.R. Grace and Company obtained a patent for the work done at the Animal Science lab, and like Grenada Genetics and other biotechnology corporations of the time, commercialized the process of cloning cattle embryos.