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Since specific genes turn on and of in specific stages and in different cells during the process of development and groups of differentiated cells combine to form different tissues and ergans. Studies have shown that the regulation of early processes of development takes place through the cytoplasmic determinans of the zygote which is transmitted only by the mother. The major role of the zygote genome in the regulation of development begins at the 8 - 16 cell stage. Several genes which participate in the regulation of development and differentian have been recognized . Some of these genes, through the effect they have on the interaction between cells, regulate the early stages of development of the embryo. Probably some of the protooncogenes have a role in the generation of the diffeientiated nerve cells, blood cells and other cells. Likewise some of the other proto - oncogenes and interferones which are made by a group of polygenes have a role in the regulation of the activity of some other proto - oncogenes. Furthermore it has been determined that some heat shock genes at different stags of development are activated in specific tissues, indicating their participation in the development of the embryo. In this article the possible role of some of the genes mentioned above is briefly discussed.