Syntheses of DNA and chromosomal proteins in the rat thymus following whole-body X-irradiation.
Syntheses of chromosomal proteins was studied in relation to DNA syntheses in the rat thymus following whole-body X-irradiation (600 rad). There was a considerable depression of the syntheses of DNA and histones during the first 4--48 hours after irradiation. The syntheses of histones H3 and H4 plus H2A were affected to a much greater degree than those of histones H1 and H2B, suggesting a tight coupling between the syntheses of DNA and histones H3 and H4 plus H2A. A part of the lysine-rich histones H1 and H2B, however, seems to be synthesized, even in the absence of DNA synthesis. Biosynthesis of non-histone proteins was also depressed in the thymus after irradiation. The degree of inhibition, however, was very low, except for the syntheses of a few non-histone protein components which were depressed to a considerable extent. This implies that the synthesis of the majority of non-histone proteins is independent of DNA synthesis.
D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000096:biosynthesis*; D002875:Chromosomes / Q000528:radiation effects*; D004247:DNA / Q000096:biosynthesis* / Q000528:radiation effects; D004261:DNA Replication / Q000528:radiation effects*; D006657:Histones / Q000096:biosynthesis*; D008297:Male; D008970:Molecular Weight; D009698:Nucleoproteins / Q000528:radiation effects; D051381:Rats; D013950:Thymus Gland / Q000378:metabolism / Q000528:radiation effects*
D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009698:Nucleoproteins; D004247:DNA