[Proliferation and differentiation in the development of myoneural tissue in birds].

Using the alkaline dissociation technique in the ciliary-iris complex of chick embryos 5-19 days of development by mean of 3H-thymidine and 3H-leucine radiography, qualitative cytochemistry and morphometry methods morpho-functional parameters of cell and simplast development in the myoneural tissue have been studied. As a result of divergent differentiation of the stem cells two differons are formed in the myoneural tissue: cellular and simplastic. They both interact in composition of the muscle fiber. The proliferation is specific for the cellular differon, and synthesis of specific proteins takes place in the simplasts. The proliferation and differentiation in the avian myoneural tissue occur on the base of competitive+ type of metabolism, while in the iris pigmentocytes--on the base of non-competitive++ interaction of DNA and specific protein synthesis. A conclusion is made concerning common mechanisms of development for the skeletal muscle and myoneural tissues. They are based on the single type of interaction of proliferation and differentiation processes in histogenesis of the two tissues.