A genomic and epigenomic view of human centromeres

Human centromeres are large, complex chromosomal loci that serve as the foundation for kinetochore assembly, contribute to chromosome architecture and sister chromatid cohesion, and participate in chromosome separation during cell division. Encoded by thousands to millions of base pairs of repetitive DNA, these regions were previously represented as gaps in the human genome assembly due to limitations in sequencing technologies and computational tools that could accurately distinguish and anchor the highly similar repeats within a linear genome assembly. Substantial advances in long-read sequencing over the past 5 years have permitted these large human centromere regions to be spanned, revealing new genomic and epigenomic information and the structural organization of these essential regions. Here, we review these discoveries and discuss knowledge gaps that have been filled and emerging functional questions.