Changes of non-histone protein fractions during embryonic development of chicken liver

Electrophoretic profiles of [3H] tryptophan labelled non-histone chromatin protein fractions of liver were studied during the embryonic development of chicken. In embryonic chicken liver a characteristic of non-histone chromatin protein fraction K (molecular weight 18 000) was synthesized. The synthesis of this fraction changed quantitatively during various days of chicken development. The greatest changes of non-histone chromatin proteins were observed on the 21st day of development (day of hatch), when besides the synthesis of a group of low molecular weight proteins (fractions J,K,L,M) the synthesis of fractions of non-histone proteins of high molecular weight was also higher than on other days. Significantly, a high molecular weight fraction, not analyzable in 7.5% PAGE, was present only in the early days (7th-12th) of our investigations.