The gap junctional protein INX-14 functions in oocyte precursors to promote C. elegans sperm guidance

Dev Biol. 2011 Nov 1;359(1):47-58. doi: 10.1016/j.ydbio.2011.08.014. Epub 2011 Aug 25.


Innexins are the subunits of invertebrate gap junctions. Here we show that the innexin INX-14 promotes sperm guidance to the fertilization site in the Caenorhabditis elegans hermaphrodite reproductive tract. inx-14 loss causes cell nonautonomous defects in sperm migration velocity and directional velocity. Results from genetic and immunocytochemical analyses provide strong evidence that INX-14 acts in transcriptionally active oocyte precursors in the distal gonad, not in transcriptionally inactive oocytes that synthesize prostaglandin sperm-attracting cues. Somatic gonadal sheath cell interaction is necessary for INX-14 function, likely via INX-8 and INX-9 expressed in sheath cells. However, electron microscopy has not identified gap junctions in oocyte precursors, suggesting that INX-14 acts in a channel-independent manner or INX-14 channels are difficult to document. INX-14 promotes prostaglandin signaling to sperm at a step after F-series prostaglandin synthesis in oocytes. Taken together, our results support the model that INX-14 functions in a somatic gonad/germ cell signaling mechanism essential for sperm function. We propose that this mechanism regulates the transcription of a factor(s) that modulates prostaglandin metabolism, transport, or activity in the reproductive tract.

Publication types

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

MeSH terms

  • Animals
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins / physiology*
  • Chromatography, Liquid
  • Fatty Acids / administration & dosage
  • Female
  • Gap Junctions / metabolism*
  • Male
  • Microinjections
  • Prostaglandins / metabolism
  • RNA Interference
  • Signal Transduction
  • Spectrometry, Mass, Electrospray Ionization
  • Spermatozoa / cytology*
  • Tandem Mass Spectrometry
  • Transcription Factors / metabolism


  • Caenorhabditis elegans Proteins
  • Fatty Acids
  • Prostaglandins
  • Transcription Factors