Trichostatin A and 5-azacytidine both cause an increase in global histone H4 acetylation and a decrease in global DNA and H3K9 methylation during mitosis in maize.
BACKGROUND
Modifications of DNA and histones in various combinations are correlated with many cellular processes. In this study, we investigated the possible relationship between histone H4 tetraacetylation, DNA methylation and histone H3 dimethylation at lysine 9 during mitosis in maize root meristems.


RESULTS
Treatment with trichostatin A, which inhibits histone deacetylases, resulted in increased histone H4 acetylation accompanied by the decondensation of interphase chromatin and a decrease in both global H3K9 dimethylation and DNA methylation during mitosis in maize root tip cells. These observations suggest that histone acetylation may affect DNA and histone methylation during mitosis. Treatment with 5-azacytidine, a cytosine analog that reduces DNA methylation, caused chromatin decondensation and mediated an increase in H4 acetylation, in addition to reduced DNA methylation and H3K9 dimethylation during interphase and mitosis. These results suggest that decreased DNA methylation causes a reduction in H3K9 dimethylation and an increase in H4 acetylation.


CONCLUSIONS
The interchangeable effects of 5-azacytidine and trichostatin A on H4 acetylation, DNA methylation and H3K9 dimethylation indicate a mutually reinforcing action between histone acetylation, DNA methylation and histone methylation with respect to chromatin modification. Treatment with trichostatin A and 5-azacytidine treatment caused a decrease in the mitotic index, suggesting that H4 deacetylation and DNA and H3K9 methylation may contain the necessary information for triggering mitosis in maize root tips.
Yang
Fei
F
Key laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Zhang
Lu
L
Li
Jun
J
Huang
Jing
J
Wen
Ruoyu
R
Ma
Lu
L
Zhou
Dongfeng
D
Li
Lijia
L
D000107:Acetylation / Q000187:drug effects; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology*; D002843:Chromatin / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006657:Histones / Q000378:metabolism*; D006877:Hydroxamic Acids / Q000494:pharmacology*; D007399:Interphase / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects*; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism
D002843:Chromatin; D004791:Enzyme Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; C012589:trichostatin A; D001374:Azacitidine