Structure, composition and evolution of the nonvital B chromosome of maize

To determine the centromere of the maize B chromosome, we used previously published anti-CENH3-ChIP-seq data from TB-9Sb, which contain a complete functional B centromere. Distribution of centromere-specific DNA repeats, including CentC, CRM element and B-repeat, were observed in the proximal end of the assembled maize B chromosome, and this region was shown to be associated with CENH3 nucleosomes. Furthermore, six small scaffolds with sizes ranging from 10 to 174 kilobase display CENH3 enrichment, also with the distribution of these repeat sequences. These results were consistent with previously cytogenetic observation. Therefore, approximately 520 kb centromeric regions were determined in the assembled maize B chromosome. MNase-seq was carried out using material from young leaves of B73 +2B. ------------------------------ *This dataset consists of 1 control sample only