Capturing Chromosome Conformation Across Length Scales

J Vis Exp. 2023 Jan 20:(191):10.3791/64001. doi: 10.3791/64001.

Abstract

Chromosome conformation capture (3C) is used to detect three-dimensional chromatin interactions. Typically, chemical crosslinking with formaldehyde (FA) is used to fix chromatin interactions. Then, chromatin digestion with a restriction enzyme and subsequent religation of fragment ends converts three-dimensional (3D) proximity into unique ligation products. Finally, after reversal of crosslinks, protein removal, and DNA isolation, DNA is sheared and prepared for high-throughput sequencing. The frequency of proximity ligation of pairs of loci is a measure of the frequency of their colocalization in three-dimensional space in a cell population. A sequenced Hi-C library provides genome-wide information on interaction frequencies between all pairs of loci. The resolution and precision of Hi-C relies on efficient crosslinking that maintains chromatin contacts and frequent and uniform fragmentation of the chromatin. This paper describes an improved in situ Hi-C protocol, Hi-C 3.0, that increases the efficiency of crosslinking by combining two crosslinkers (formaldehyde [FA] and disuccinimidyl glutarate [DSG]), followed by finer digestion using two restriction enzymes (DpnII and DdeI). Hi-C 3.0 is a single protocol for the accurate quantification of genome folding features at smaller scales such as loops and topologically associating domains (TADs), as well as features at larger nucleus-wide scales such as compartments.

Publication types

  • Video-Audio Media

MeSH terms

  • Cell Nucleus / metabolism
  • Chromatin* / genetics
  • Chromosomes* / genetics
  • Chromosomes* / metabolism
  • DNA / chemistry
  • DNA / genetics
  • DNA Restriction Enzymes / metabolism
  • Formaldehyde / chemistry
  • Nucleic Acid Conformation

Substances

  • Chromatin
  • DNA
  • DNA Restriction Enzymes
  • Formaldehyde