Chromosome regions enriched in hyperacetylated histone H4 are preferred sites for endonuclease- and radiation-induced breakpoints.
Previously, we have shown that breakpoints induced by the endonucleases AluI, BamHI and DNase I in CHO chromosomes are localized mainly in G-light bands. Neutrons and gamma rays produced similar breakpoint clusters to endonucleases in most CHO chromosomes. Here we compare endonuclease- and radiation-induced breakpoint maps with hyperacetylation patterns of histone H4. The H4 acetylation pattern in chromosomes is similar to the pattern of G-light, or R-bands, and breakpoints are clustered in highly acetylated chromosome regions. These findings indicate that chromosomal aberrations occur more frequently in active than in inactive chromatin.
Faculty of Sciences, University of the Republic, Montevideo, Uruguay. wlopez@iibce.edu.uy
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D000107:Acetylation; D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D002871:Chromosome Banding; D002875:Chromosomes / Q000187:drug effects* / Q000528:radiation effects*; D006224:Cricetinae; D004249:DNA Damage; D004720:Endonucleases / Q000378:metabolism*; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007621:Karyotyping; D014158:Transcription, Genetic
D002843:Chromatin; D006657:Histones; D004720:Endonucleases