The Sperm TRP-3 Channel Mediates the Onset of a Ca(2+) Wave in the Fertilized C. elegans Oocyte

Cell Rep. 2016 Apr 19;15(3):625-637. doi: 10.1016/j.celrep.2016.03.040. Epub 2016 Apr 7.

Abstract

Sperm induce Ca(2+) waves in the fertilized egg by introducing soluble factors or by surface interactions, which activate egg Ca(2+) channels. Involvement of sperm Ca(2+) channels is predicted by the conduit model; however, this model has not been validated. In Caenorhabditis elegans, the sperm-specific TRP family Ca(2+) channel TRP-3 mediates sperm-oocyte fusion. Here, using high-speed in vivo imaging and image analyses, we show that sperm induce an immediate local Ca(2+) rise followed by a Ca(2+) wave in fertilized C. elegans oocytes. Oocytes fertilized by rare trp-3 escaper sperm showed a lack of local rise and a delay in onset of the Ca(2+) wave. Sperm Ca(2+) imaging suggests that the local rise is not due to the bolus introduction of stored Ca(2+). These results suggest that, along with its primary function in sperm-oocyte fusion, TRP-3 induces Ca(2+) waves in fertilized oocytes, consistent with the conduit model.

Publication types

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

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins / metabolism*
  • Calcium Channels / metabolism*
  • Calcium Signaling*
  • Fertilization*
  • Gene Expression Regulation, Developmental
  • Genetic Loci
  • Homeostasis
  • Male
  • Membrane Fusion
  • Models, Biological
  • Oocytes / cytology
  • Oocytes / metabolism*
  • Spermatozoa / metabolism*
  • Time Factors
  • Transgenes

Substances

  • Caenorhabditis elegans Proteins
  • Calcium Channels
  • spe-41 protein, C elegans