Rapid de novo centromere formation occurs independently of heterochromatin protein 1 in C. elegans embryos

Curr Biol. 2011 Nov 8;21(21):1800-7. doi: 10.1016/j.cub.2011.09.016. Epub 2011 Oct 20.


DNA injected into the Caenorhabditis elegans germline forms extrachromosomal arrays that segregate during cell division [1, 2]. The mechanisms underlying array formation and segregation are not known. Here, we show that extrachromosomal arrays form de novo centromeres at high frequency, providing unique access to a process that occurs with extremely low frequency in other systems [3-8]. De novo centromerized arrays recruit centromeric chromatin and kinetochore proteins and autonomously segregate on the spindle. Live imaging following DNA injection revealed that arrays form after oocyte fertilization via homologous recombination and nonhomologous end-joining. Individual arrays gradually transition from passive inheritance to active segregation during the early embryonic divisions. The heterochromatin protein 1 (HP1) family proteins HPL-1 and HPL-2 are dispensable for de novo centromerization even though arrays become strongly enriched for the heterochromatin-associated H3K9me3 modification over time. Partial inhibition of HP1 family proteins accelerates the acquisition of segregation competence. In addition to reporting the first direct visualization of new centromere formation in living cells, these findings reveal that naked DNA rapidly builds de novo centromeres in C. elegans embryos in an HP1-independent manner and suggest that, rather than being a prerequisite, HP1-dependent heterochromatin antagonizes de novo centromerization.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Centromere / metabolism*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism
  • DNA, Helminth / metabolism*
  • Homologous Recombination
  • Kinetochores / metabolism


  • Caenorhabditis elegans Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA, Helminth
  • HPL-1 protein, C elegans
  • HPL-2 protein, C elegans