A Conserved Chromatin Architecture Marks and Maintains the Restricted Germ Cell Lineage in Worms and Flies

Dev Cell. 2003 Nov;5(5):747-57. doi: 10.1016/s1534-5807(03)00327-7.

Abstract

In C. elegans, mRNA production is initially repressed in the embryonic germline by a protein unique to C. elegans germ cells, PIE-1. PIE-1 is degraded upon the birth of the germ cell precursors, Z2 and Z3. We have identified a chromatin-based mechanism that succeeds PIE-1 repression in these cells. A subset of nucleosomal histone modifications, methylated lysine 4 on histone H3 (H3meK4) and acetylated lysine 8 on histone H4 (H4acetylK8), are globally lost and the DNA appears more condensed. This coincides with PIE-1 degradation and requires that germline identity is not disrupted. Drosophila pole cell chromatin also lacks H3meK4, indicating that a unique chromatin architecture is a conserved feature of embryonic germ cells. Regulation of the germline-specific chromatin architecture requires functional nanos activity in both organisms. These results indicate that genome-wide repression via a nanos-regulated, germ cell-specific chromatin organization is a conserved feature of germline maintenance during embryogenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blastomeres / cytology
  • Blastomeres / physiology
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / embryology
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Cell Lineage*
  • Chromatin / metabolism*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / genetics*
  • Germ Cells / physiology*
  • Histones / metabolism
  • Methylation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Nucleic Acid Conformation*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • Transcription Factors / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • Chromatin
  • Drosophila Proteins
  • Histones
  • MEP-1 protein, C elegans
  • Nuclear Proteins
  • RNA-Binding Proteins
  • Transcription Factors
  • pie-1 protein, C elegans
  • nos protein, Drosophila