Dynamic Centromeres Under Epigenetic Constraint.

Centromeres are essential chromosomal loci specified epigenetically by CENP-A chromatin, yet they undergo rapid sequence turnover, structural remodeling, and occasional repositioning. In this review, we integrate recent advances enabled by long-read genome assemblies and high-resolution chromatin mapping to synthesize current understanding of centromere organization across taxa. We examine how satellite repeats, transposable elements, molecular drive, and meiotic conflict generate extreme centromere diversity. We further explore how DNA methylation and H3K9me3 heterochromatin constrain CENP-A positioning, stabilize centromeric domains, and shape boundary dynamics during centromere drift, duplication, and de novo formation. Together, these perspectives show how centromeres accommodate evolutionary change while preserving the stringent requirements of faithful chromosome segregation.