Developmental changes in non-histone chromosomal proteins of bullfrog (Rana catesbeiana)

1. Chromatins were isolated from liver, brain, kidney, spleen, heart muscle and erythrocytes of the bullfrog and its tadpole, Rana catesbeiana and their non-histone chromosomal proteins (NHC proteins) were compared by a simple electrophoretic method. 2. No qualitative but quantitative variations in the composition of NHC proteins were found among the tissues examine. 3. The tissue of tadpole and frog were classified into three groups according to their electrophoretic pattern of NHC proteins' brain, heart muscle and spleen showing almost the same pattern, liver and kidney showing different pattern in some components, and erythrocytes showing markedly different pattern. 4. Component D3 occurring i the frog liver, not in the tadpole, was found to increase in the tadpole liver during natural and thyroxine-induced metamorphosis.