Chromatin characteristics of carcinogen-treated avian erythrocyte nuclei and effects of reactivation.
We have examined nucleosome repeat length and accessibility of erythrocyte nuclei to micrococcal nuclease before and after reactivation of the erythrocytes by fusion with A9 cells, and also after treatment with the alkylating agent N-methyl-N-nitrosourea (MNU). We have found that the repeat length is higher for adult than for embryonic nuclei (227 and 202 base pairs, respectively) and after reactivation the value decreases (to 183 +/- 2 bp and 172 +/- 4 bp, respectively). Values for MNU-treated, reactivated nuclei are slightly (but probably not significantly) higher (188 bp and 176 +/- 1 bp) than for corresponding untreated nuclei. However, the rate of digestion is lower in MNU-treated erythrocytes, both unreactivated and reactivated, than in the corresponding untreated nuclei.
Guy
S P
SP
Department of Optometry and Vision Sciences, U.M.I.S.T., Manchester.
Bradshaw
T K
TK
Itzhaki
R F
RF
D000818:Animals; D002459:Cell Fusion; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis / Q000187:drug effects; D002645:Chickens / Q000097:blood; D004247:DNA / Q000032:analysis*; D004912:Erythrocytes / Q000187:drug effects* / Q000502:physiology; D008770:Methylnitrosourea / Q000494:pharmacology*; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000032:analysis / Q000187:drug effects*
D009707:Nucleosomes; D008770:Methylnitrosourea; D004247:DNA; D008836:Micrococcal Nuclease