Figure 2.

Proposed Role of Repetitive Sequences in Centromeres

We postulate that the kinetochore location might be able to “drift” on the DNA. If a kinetochore moved over a gene, then it would suppress its expression. This would be deleterious for essential genes. At nonrepetitive centromeres, the probability of this drift affecting a flanking gene is higher than at repetitive centromeres, where the probability of affecting a gene is relatively low. We suggest that repetitive sequences might provide a safety area for centromere “drift.” Pericentromere regions at edge of centromeres might also function as a heterochromatin barrier between centromere and euchromatin regions.