Figure 7. Assembly of 237 NHP centromeres reveals variation in α-satellite HOR array size, structure, and composition.

a) Sequence and structure of α-satellite HOR arrays from the human (T2T-CHM13), bonobo, chimpanzee, gorilla, Bornean orangutan, and Sumatran orangutan chromosome 1–5 centromeres, with the α-satellite suprachromosomal family (SF) indicated for each centromere. The sequence and structure of all completely assembled centromeres is shown in Fig. CENSATS1. b) Variation in the length of the α-satellite HOR arrays for NHP centromeres. Bonobo centromeres have a bimodal length distribution, with 28 chromosomes showing “minicentromeres” (with α-satellite HOR arrays <700 kbp long). c) Correlation between the length of the bonobo active α-satellite HOR array and the length of the CDR for the same chromosome. d) Example showing that the bonobo and chimpanzee chromosome 1 centromeres are divergent in size despite being from orthologous chromosomes. e) Sequence identity heatmap between the chromosome 17 centromeres from bonobo and chimpanzee show a common origin of sequence as well as the birth of new α-satellite HORs in the chimpanzee lineage. f) Sequence identity heatmap between the chromosome 5 centromeres from the Bornean and Sumatran orangutans show highly similar sequence and structure, except for one pocket of α-satellite HORs that is only present in the Bornean orangutan. *, p < 0.05; n.s., not significant.