Genome-wide maps of heterochromatin state (H3K9me2) in kinetochore and other centromere related mutants.

We report the high-throughput profiling of histone modification (H3K9me2) in fission yeast Schizosaccharomyces pombe. By obtaining 1-10 ng immunoprecipitated DNA, we generated genome-wide H3K9me2 maps of fission yeast mutants with either deletions of non-essential kinetochore genes or conditional inactivation (temperature sensitive, ts) mutations in essential ones. We find that the impairment of the kinetochore componnets cause various levels (from no to prominent) of heterochroamatin spreading into centromeric core regions. Hence, we conclude that the integrity of the inner kinetochore is required to maintain normal centromeric chromatin organization as well as distinct centromere identity. 2 outer kinetochore ts mutants, 7 inner kinetochore mutants and 4 mutants of genes encoding centromere-interacting proteins or histone chaperones were examined. All ts mutants are cultured under permissive condition (26 °C) and non-permissive condition (26 °C shifted to 36 °C for 3-4 h). In anti-H3K9me2 ChIP-seq experiments, only mhf2∆ and cnp3∆fta6∆ had two biological replicates, the remaining samples were examined only once.