W618 The Euchromatic Characteristics Associated With Rice Centromeres

Date: Sunday, January 15, 2012
Time: 12:00 PM
Room: Golden West
Jiming Jiang , University of Wisconsin-Madison, Madison, WI
The centromeres are embedded within the pericentromeric heterochromatin in most higher eukaryotes.  Thus, centromere has been viewed as a heterochromatic chromosomal domain.  Interestingly, euchromatic characteristics associated with centromeric chromatin, which is defined by presence of the centromere-specific histone CENH3, were reported in both animal and plant species. The centromeres of four rice chromosomes (Cen4, Cen5, Cen7, Cen8) have been fully or nearly fully sequenced. The core domains of these four centromeres are composed of alternating blocks of H3 and CENH3 nucleosomes. We developed a genomic tiling array for these four rice centromeres. A ChIP-chip approach was used to study the patterns of four euchromatic histone modification marks (H3K4me2, H3K4me3, H3K36me3 and H3K4K9ac) associated with rice centromeres. The vast majority of the four histone marks were associated with genes located in the H3 subdomains within the centromeric cores. We demonstrate that the euchromatic characteristics of rice centromeric chromatin are trademarks of the transcribed sequences embedded in the centromeric H3 subdomains in rice centromeres.