cut the supply of nutrients and thereby induced the donor cell to go into a quiescent phase in which the cell stopped dividing. In this way, they were able to prepare the donor nucleus so that it would be compatible with the egg cytoplasm. This also enabled the transmuted nuclei to become reprogrammed so that it could create every other kind of cell. The cells became capable of retaining all genetic material necessary to produce a complete organism, given that every totipotent cell carries a complete set of genes for an organism. The reprogramming that takes place in the two-way transfer of proteins between the nucleus and the cytoplasm effects the de-differentiation of cells and allows them to become totipotent. The difficulty with which Wilmut et al. produced one healthy lamb is illustrated by the fact that they obtained this result after beginning their experiment with 434 sheep oocytes. Of these, only 277 adult nuclei were transferred successfully to enucleated oocytes. The success rate of only 1 out of 434 oocytes indicates that cloning is not only inefficient, but also an exceedingly complicated biological process involving many different causal factors.
Recently, scientists Rudolf Jaenisch of MIT and Ryuzo Yanagimachi of the University of Hawaii have concluded that "the process of cloning introduces genetic mutations and there seems no immediate way around the problem it is very irresponsible to think this method could be used for the reproduction of cloning humans." This discovery only complicates an already complex process and emphasizes the concern of its moral permissibibility.
However, if humans were to be cloned, the process would go something like this: Scientists and doctors would harvest up to 15 eggs from 40 different female donors, producing approximately 600 eggs and, in addition, they would also collect cells from the person to be cloned. They would then extract the nucleus by means of a fine needle from the eggs and put the recently vacant egg and the cloner's cells next to each other, and zap them with electricity.
