EXPLANT SYSTEMS AND THE REACTIONS OF GASTRULATING AMPHIBIANS TO METABOLIC POISONS

Abstract

An attempt was made to analyze the movements of parts of gastrulating Rana pipiens embryos by observing the effects of various inhibitory environments on explant model systems. The test systems were based on Holtfreter''s directions for constructing given combinations of explants. Metabolic poisons employed were 0.005 [image] Na azide, 0.040-0.045 [image]Na malonate, 5 x 10_6 [image]p-chloromercuribenzoic acid, 1.1 x 10-4 [image] 2,4- dinitrophenol, 0.05 [image] Na barbital, 0.05-0.1 [image] urethane and anaerobiosis (95 N2:5 CO2) at appropriate pH values. Differential effects of these inhibitors on bottle-cell formation, convergent stretching, and epibolic expansion as expressed by the explant systems suggest that this exptl. approach, with refinements, may lead to a better understanding of the morphogenetic failure of whole embryos exposed to similar treatment. As a part of the over-all study of gastrular metabolism, it was shown that there is no acceleration of glycolysis in isolated gastrula parts kept under anaerobiosis.