Mutations in genes encoding extracellular matrix proteins suppress the emb-5 gastrulation defect in Caenorhabditis elegans

Mol Gen Genet. 1998 Jul;259(1):2-12. doi: 10.1007/s004380050782.


The second division of the gut precursor E cells is lethally accelerated during Caenorhabditis elegans gastrulation by mutations in the emb-5 gene, which encodes a presumed nuclear protein. We have isolated suppressor mutations of the temperature-sensitive allele emb-5(hc61), screened for them among dpy and other mutations routinely used as genetic markers, and identified eight emb-5 suppressor genes. Of these eight suppressor genes, at least four encode extracellular matrix proteins, i.e., three collagens and one proteoglycan. The suppression of the emb-5 gastrulation defect seemed to require the maternal expression of the suppressors. Phenotypically, the suppressors by themselves slowed down early embryonic cell divisions and corrected the abnormal cell-division sequence of emb-5 mutant embryos. We propose an indirect stress-response mechanism to be the main cause of the suppression because: (1) none of these suppressors is specific, either to particular temperature-sensitive emb-5 alleles or to the emb-5 gene; (2) suppressible alleles of genes, reported here or elsewhere, are temperature sensitive or weak; (3) the suppression is not strong but marginal; (4) the suppression itself shows some degree of temperature dependency; and (5) none of the extracellular matrix proteins identified here is known to be expressed in oocytes or early embryos, despite the present observation that the suppression is maternal.

Publication types

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

MeSH terms

  • Alleles
  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins*
  • Cell Division / genetics
  • Collagen / genetics
  • Embryo, Nonmammalian / physiology
  • Extracellular Matrix Proteins / genetics*
  • Extracellular Matrix Proteins / physiology*
  • Gastrula / metabolism
  • Gastrula / physiology*
  • Gene Expression Regulation, Developmental
  • Genes / genetics*
  • Genes, Suppressor / genetics*
  • Genotype
  • Glucagon / genetics
  • Glucagon-Like Peptide 1
  • Helminth Proteins / genetics*
  • Molecular Chaperones / physiology
  • Mutation*
  • Peptide Fragments / genetics
  • Phenotype
  • Protein Precursors / genetics
  • Proteoglycans / genetics
  • Temperature
  • Transcription Factors / genetics*


  • Caenorhabditis elegans Proteins
  • Emb-5 protein, C elegans
  • Extracellular Matrix Proteins
  • Helminth Proteins
  • Molecular Chaperones
  • Peptide Fragments
  • Protein Precursors
  • Proteoglycans
  • Transcription Factors
  • Glucagon-Like Peptide 1
  • Collagen
  • Glucagon