Histone modifications associated with both A and B chromosomes of maize.
We report the distribution of several histone modifications along the arms and in centromeric regions of somatic chromosomes of maize, including the supernumerary B chromosome. Acetylated H3 and H4 as well as H3K4me2, modifications associated with euchromatin, were enriched in the distal parts of the A chromosomes, but were progressively depleted toward the centromeres of the A chromosomes and were depleted in the heterochromatic portions of the B chromosome. Classical histone modifications associated with heterochromatin, including H3K9me2, H3K27me1 and H3K27me2, were distributed throughout both A and B chromosomes. However, H3K27me2 showed a reduced level on the B chromosome compared with the A chromosomes and was not associated with some classes of constitutive heterochromatin. We monitored the presence of each histone modification in the centromeric regions using a YFP-tagged centromere-specific histone, CENH3. We observed the presence of H3K9me2 and absence of H3K4me2 in the centromeric regions of both A and B chromosomes of maize, which is in contrast to the presence of H3K4me2 and absence of H3K9me2 in animal centromeres. These results show a diversity of epigenetic modifications associated with centromeric chromatin in different eukaryotes.
Jin
Weiwei
W
Department of Horticulture, University of Wisconsin-Madison, Madison, WI 53706, USA.
Lamb
Jonathan C
JC
Zhang
Wenli
W
Kolano
Bozena
B
Birchler
James A
JA
Jiang
Jiming
J
D002843:Chromatin / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D044127:Epigenesis, Genetic / Q000235:genetics*; D005455:Fluorescent Antibody Technique; D006657:Histones / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D003313:Zea mays / Q000235:genetics*
D002843:Chromatin; D017931:DNA Primers; D006657:Histones