Pan-conserved segment tags identify ultra-conserved sequences across assemblies in the human pangenome

Cell Rep Methods. 2023 Aug 2;3(8):100543. doi: 10.1016/j.crmeth.2023.100543. eCollection 2023 Aug 28.

Abstract

The human pangenome, a new reference sequence, addresses many limitations of the current GRCh38 reference. The first release is based on 94 high-quality haploid assemblies from individuals with diverse backgrounds. We employed a k-mer indexing strategy for comparative analysis across multiple assemblies, including the pangenome reference, GRCh38, and CHM13, a telomere-to-telomere reference assembly. Our k-mer indexing approach enabled us to identify a valuable collection of universally conserved sequences across all assemblies, referred to as "pan-conserved segment tags" (PSTs). By examining intervals between these segments, we discerned highly conserved genomic segments and those with structurally related polymorphisms. We found 60,764 polymorphic intervals with unique geo-ethnic features in the pangenome reference. In this study, we utilized ultra-conserved sequences (PSTs) to forge a link between human pangenome assemblies and reference genomes. This methodology enables the examination of any sequence of interest within the pangenome, using the reference genome as a comparative framework.

Keywords: k-mer; pan-conserved segment; pangenome; reference genome; structural polymorphism; structural variations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Conserved Sequence
  • Haploidy
  • Humans
  • Neoplasms, Squamous Cell*
  • Polymorphism, Genetic
  • Skin Neoplasms*