The C. elegans spe-9 gene encodes a sperm transmembrane protein that contains EGF-like repeats and is required for fertilization

Cell. 1998 Apr 3;93(1):71-9. doi: 10.1016/s0092-8674(00)81147-2.


In the nematode worm C. elegans, individuals with mutations in the spe-9 gene produce spermatozoa with wild-type morphology and motility that cannot fertilize oocytes even after contact between gametes. Therefore, disruption of spe-9 function affects either gamete recognition, adhesion, signaling, and/or fusion. The spe-9 gene encodes a sperm transmembrane protein with an extracellular domain that contains ten epidermal growth factor-like repeats. A common feature of proteins that include epidermal growth factor-like motifs is their involvement in extracellular functions such as adhesive and ligand-receptor interactions. Additionally, the overall structure of the predicted SPE-9 protein is similar to that of ligands for the Notch/LIN-12/GLP-1 family of transmembrane receptors. These results suggest that SPE-9 functions in the specialized cell-cell interactions required for fertilization.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins*
  • Cloning, Molecular
  • Disorders of Sex Development
  • Epidermal Growth Factor / chemistry
  • Female
  • Fertilization / physiology*
  • Genes, Helminth
  • Germ Cells / physiology
  • Male
  • Membrane Proteins / biosynthesis*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Molecular Sequence Data
  • Ovulation
  • Polymerase Chain Reaction
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Sperm Motility
  • Sperm-Ovum Interactions / physiology
  • Spermatozoa / physiology*


  • Caenorhabditis elegans Proteins
  • Membrane Proteins
  • Recombinant Proteins
  • Spe-9 protein, C elegans
  • Epidermal Growth Factor

Associated data

  • GENBANK/AF049327