Hemoglobin chains during foetal development in mice.

Hemoglobin components present in C3H mice during foetal development were investigated. Two major embryonic hemoglobins were found, one composed of alpha and non-alpha globin chains and the other of non-alpha chains only. No foetal hemoglobin different from the adult ane embryonic hemoglobins was detected. The preparation of adult C3H alpha chain is a mixture of two alpha chains: one comprising 70 per cent of the whole amount is identical with the alpha-chain of the C57B1 strain of mice while the other 30 per cent is identical with the alpha chain of NB strain. The synthesis of these two chains is not activated at the same time during foetal development. No C57B1 alpha chain is synthesized by foetal erythrocytes on the 13th day of gestation whereas on the 18th day the synthesis of C57B1 chain is the same in the foetus and in the adult C3H mouse.