Amino acid transport and protein synthesis in induced ectoderm of amphibian embryos.

Isolated gastrula ectoderm ofTriturus alpestris orAmbystoma mexicanum was induced by the vegetalizing factor. Protein synthesis in the induced and uninduced control explants was measured by double labelling with3H-and14C-amino acids after different periods of cultivation. Slight differences were observed in the pattern of nuclear proteins after 12 h of cultivation and in the pattern of cytoplasmic proteins after 48 h of cultivation.The uptake of leucine started to increase in induced explants after 48 h of cultivation and after 96 h was about 50 times greater than in uninduced control explants. The uptake is reduced under partially anaerobic conditions. Ouabain inhibits the uptake by about 50%.