Genetics of Lipid-Storage Management in Caenorhabditis elegans Embryos

Genetics. 2016 Mar;202(3):1071-83. doi: 10.1534/genetics.115.179127. Epub 2016 Jan 15.


Lipids play a pivotal role in embryogenesis as structural components of cellular membranes, as a source of energy, and as signaling molecules. On the basis of a collection of temperature-sensitive embryonic lethal mutants, a systematic database search, and a subsequent microscopic analysis of >300 interference RNA (RNAi)-treated/mutant worms, we identified a couple of evolutionary conserved genes associated with lipid storage in Caenorhabditis elegans embryos. The genes include cpl-1 (cathepsin L-like cysteine protease), ccz-1 (guanine nucleotide exchange factor subunit), and asm-3 (acid sphingomyelinase), which is closely related to the human Niemann-Pick disease-causing gene SMPD1. The respective mutant embryos accumulate enlarged droplets of neutral lipids (cpl-1) and yolk-containing lipid droplets (ccz-1) or have larger genuine lipid droplets (asm-3). The asm-3 mutant embryos additionally showed an enhanced resistance against C band ultraviolet (UV-C) light. Herein we propose that cpl-1, ccz-1, and asm-3 are genes required for the processing of lipid-containing droplets in C. elegans embryos. Owing to the high levels of conservation, the identified genes are also useful in studies of embryonic lipid storage in other organisms.

Keywords: C. elegans; embryo development; embryonic lipid droplets; essential genes; yolk.

MeSH terms

  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cathepsin L / genetics
  • Cathepsin L / metabolism*
  • Embryonic Development
  • Lipid Metabolism / genetics*
  • Mutation
  • RNA Interference
  • Sphingomyelin Phosphodiesterase / genetics
  • Sphingomyelin Phosphodiesterase / metabolism*
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*


  • CCZ-1 protein, C elegans
  • Caenorhabditis elegans Proteins
  • Vesicular Transport Proteins
  • ASM-3 protein, C elegans
  • Sphingomyelin Phosphodiesterase
  • CPL-1 protein, C elegans
  • Cathepsin L