Changes in the H-1 histone complement during myogenesis. I. Establishment by differential coupling of H-1 species synthesis to DNA replication.
Proportions of the four major chicken H-1 histones (referred to as H-1's a-d) change during in vitro skeletal myogenesis. As myoblasts fuse and differentiate into myotubes, the relative amount of H-1c increases dramatically. The change occurs primarily because synthesis of the H-1 species is coupled to DNA synthesis to different extents. H-1c synthesis is least tightly coupled to DNA replication in precursor myoblasts and in differentiated myotubes. Thus H-1c synthesis predominates after dividing myoblasts fuse into postmitotic myotubes. This results in the replacement of pre-existing H-1 and therefore increases the relative amount of H-1c. Differences in the stability of the H-1's are also involved in changing H-1 proportions. The results show that changes in H-1 proportions during myogenesis are a consequence of withdrawal from the cell cycle. The data provides a general mechanistic explanation of how tissue-specific H-1 proportions are established.
D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D002459:Cell Fusion; D002642:Chick Embryo; D003561:Cytarabine / Q000494:pharmacology; D004261:DNA Replication / Q000187:drug effects; D006657:Histones / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D009132:Muscles / Q000166:cytology* / Q000378:metabolism
D006657:Histones; D003561:Cytarabine