Cloning

Incidentally, this problem has not only theoretical but also practical significance. The difficulties encountered in animal cloning are largely determined by the fact that we still know too little about the work of genes during early development. Cloning of animals is carried out by transplanting a nucleus from a somatic (non-sexual) cell of one animal into the egg of another. However, for normal development, it is necessary that the genes of the embryo are initially silent, and they are quite active in the donor nucleus. The egg cytoplasm must somehow reprogram the nucleus, turn off the genome, and then turn it on again at the right time. Until we know how to help her with this, it’s hard to expect great success in cloning.