Study of the relationship between the subfraction composition of histone F1 and the type of tissue in birds.

The subfraction composition of lysine-rich histone has been studied with the aid of polyacrylamide gel electrophoresis. The subfraction compositions of the histone F1 of several tissues from the chicken, pigeon, and titmouse have been compared. The histone F1 from the tissues investigated consists of four or five subfractions of similar number and electrophoretic mobility (1, 1a, 2, 3, and 4). In the different avian species each subfraction varied its mobility independently of the others. The chicken tissues investigated can be divided into two classes, depending on the relative concentration of subfractions 2 and 3 (A and B): Class A (subfraction 2 is smaller than 3) includes the brain, liver, skeletal muscle, heart, muscular layer of the stomach, and pancreas, and class B (subfraction 2 is larger than 3) includes the intestinal mucosa, thymus, and testes, as well as the liver, heart, and pancreas from a 21-day embryo. Such a division of the tissues corresponds to the varying rate of their cellular renewal. In a parallel examination of the relative concentrations of the individual subfractions in the same tissues from the three avian species it has been found that the relative concentration of subfractions 3 and 2 is increased in the skeletal muscles, heart, brain, and liver, that subfraction 2 is increased in the intestinal mucosa, that subfractions 4 and 3 are increased in the pancreas, and that subfractions 1, 1a, and 4 are increased in the erythrocytes. The results obtained may be interpreted as a consequence of some relationship between the subfraction composition of histone F1 and the type of tissue of the source.