title: The Sperm TRP-3 Channel Mediates the Onset of a Ca(2+) Wave in the Fertilized C. elegans Oocyte.
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.
authors.affiliation: Laboratory for Developmental Dynamics, RIKEN Quantitative Biology Center, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Takayama
authors.affiliation: Laboratory for Developmental Dynamics, RIKEN Quantitative Biology Center, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan. Electronic address: sonami@riken.jp.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Onami
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000166:cytology / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling; D005306:Fertilization; D018507:Gene Expression Regulation, Developmental; D056426:Genetic Loci; D006706:Homeostasis; D008297:Male; D008561:Membrane Fusion; D008954:Models, Biological; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism*; D013997:Time Factors; D019076:Transgenes
chemical_list: D029742:Caenorhabditis elegans Proteins; D015220:Calcium Channels; C477118:spe-41 protein, C elegans