Gabrielle Hartley from the University of Connecticut presented at London Calling 2023 a lightning talk. The session’s title is “Telomere-to-telomere nanopore-based genome assembly reveals genomic and epigenetic features of karyotype radiation.” Hartley is a graduate student and is studying the evolution of gibbons. They noted that, unlike other apes, gibbons “have highly rearranged karyotypes concomitant with centromere variation.” The chromosome number ranges up to 52! Hartley’s work focuses on centromeres: regions of DNA needed for cell division and epigenetically defined. Centromeres help with the equal distribution of genetic material during cell division. Centromere protein A (CENP-A) is present at the centromeres. Hartley studied two gibbon species: Eastern hoonlock and pileated gibbons. Hartley sequenced both genomes: ~2.7 Gb each with 80X coverage. The Eastern hoonlock gibbon has a composite repeat array at the centromere locus. The identification of this repeat plays a role in the rapid evolution of the gibbon karyotype. Hartley is studying this centromere locus organization. Data supports the hypothesis that centromere repeats play a role in rapid gibbon karyotype evolution. This intriguing study was made possible thanks to long-read sequencing and genome assembly.
