The P Granules of C. elegans: A Genetic Model for the Study of RNA-Protein Condensates

J Mol Biol. 2018 Nov 2;430(23):4702-4710. doi: 10.1016/j.jmb.2018.08.007. Epub 2018 Aug 8.


P granules are RNA/protein condensates in the germline of Caenorhabditis elegans. Genetic analyses have begun to identify the proteins that regulate P granule assembly in the cytoplasm of zygotes. Among them, the RGG-domain protein PGL-3, the intrinsically disordered protein MEG-3, and the RNA helicase LAF-1 all bind and phase separate with RNA in vitro. We discuss how RNA-induced phase separation, competition with other RNA-binding proteins, and reversible phosphorylation contribute to the asymmetric localization of P granules in the cytoplasm of newly fertilized embryos. P granules contain RNA silencing complexes that monitor the germline transcriptome and may provide an RNA memory of germline gene expression across generations.

Keywords: C. elegans; Germline condensates; P granules; RNA granules.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / metabolism
  • Cytoplasmic Granules / metabolism*
  • Gene Expression Regulation, Developmental
  • In Vitro Techniques
  • Models, Genetic
  • Phase Transition
  • Phosphorylation
  • RNA / metabolism*
  • RNA-Binding Proteins / metabolism*
  • Zygote / growth & development
  • Zygote / metabolism


  • Caenorhabditis elegans Proteins
  • RNA-Binding Proteins
  • RNA