Distribution pattern of histone H3 phosphorylation at serine 10 during mitosis and meiosis in Brachiaria species.

Histones are the major eukaryotic DNA-binding proteins. Posttranslational modifications on N-terminal tails of histones that form nucleosomes are often associated with distinct biological functions. Some theories suggest that one of these modifications, the phosphorylation of histone H3 at serine 10 (H3S10ph) plays a role in both chromosome condensation and sister chromatid cohesion. Although histones and some of their modifications are highly conserved, studies have shown that role and distribution of H3S10ph may differ between species. We evaluated the pattern of H3 phosphorylation using immunodetection during mitosis and meiosis in both diploid and tetraploid genotypes of Brachiaria species. Results revealed differences in chromosome distribution of H3S10ph when mitosis and meiosis were compared. Whole chromosomes were phosphorylated during meiosis I, whereas phosphorylation was restricted to the pericentromeric region in both meiosis II and mitosis. There was no variation in phosphorylation patterns between Brachiaria species and diploid and tetraploid genotypes. Regarding spatiotemporal coordination in the Brachiaria species evaluated, H3S10ph is related to maintenance of sister chromatid cohesion during cell divisions.