[Protein synthesis in loach embryos isolated from the yolk and cultivated in vitro]

Changes in protein synthesis in the loach (Misgurnus fossilis) blastoderms cultivated in vitro in the Holtfreter solution after their separation from the yolk at the early and late-blastula stages were assessed by biochemical and autoradiographic methods. The embryos incubated in vitro at the from blastula stage are characterized by the sharp activation of protein synthesis and the vegetal-animal gradient of protein synthesis, as well as in the control embryos; such embryos gastrulate and proceed to primary differentiation. On the contrary, in the embryos incubated from the early blastula stage the protein synthesis is inhibited and no regional differences in its intensity are noted; such embryos do not proceed to gastrulation. Possible causes of the protein synthesis activation in differentiating blastoderms and interrelationship between the character of protein synthesis and the ability of embryos for differentiation are discussed. The protein synthesis activation and the vegetal-animal gradient appearance are considered as a biochemical criterion of primary differentiation during gastrulation in fish embryos.