Histone Hl° expression during developmental growth of rat liver

Abstract

Histone Hl° appears in rat liver nuclei around the time of birth; it increases to near-adult levels by 30 days of age, in waves which correlate with distinct phases of liver developmental growth. Hl° emerges as the liver terminates the bulk of its proliferative activity, but it accumulates mainly during the terminal cytodifferentiation phases leading to polyploidization. Premature interruption of liver DNA synthesis in neonatal rats, with cytosine arabinoside or dexamethasone, induces some accumulation of Hl° in the liver. Our data suggest that DNA synthesis arrest conditions in part, but is not the main developmental event underlying Hl° expression during differentiation of rat liver.