title: Store-Operated Ca2+ Entry Sustains the Fertilization Ca2+ Signal in Pig Eggs.
abstract: The role of store-operated Ca(2+) entry (SOCE) in the maintenance of sperm-induced Ca(2+) oscillations was investigated in porcine eggs. We found that 10 μM gadolinium (Gd(3+)), which is known to inhibit SOCE, blocked Ca(2+) entry that was triggered by thapsigargin-induced store depletion and also caused an abrupt cessation of the fertilization Ca(2+) signal. In a similar manner 3,5-bis(trifluoromethyl)pyrazole 2 (20 μM), and tetrapandin-2 (10 μM), potent SOCE inhibitors, also blocked thapsigargin-stimulated Ca(2+) entry and disrupted the Ca(2+) oscillations after sperm-egg fusion. The downregulation of Stim1 or Orai1 in the eggs did not alter the Ca(2+) content of the intracellular stores, whereas co-overexpression of these proteins led to the generation of irregular Ca(2+) transients after fertilization that stopped prematurely. We also found that thapsigargin completely emptied the endoplasmic reticulum, and that the series of Ca(2+) transients stopped abruptly after the addition of thapsigargin to the fertilized eggs, indicating that the proper reloading of the intracellular stores is a prerequisite for the maintenance of the Ca(2+) oscillations. These data strengthen our previous findings that in porcine eggs SOCE is a major signaling cascade that is responsible for sustaining the repetitive Ca(2+) signal at fertilization.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, Indiana.
authors.forename: Chunmin
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, Indiana.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana.
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Jaeger
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, Indiana zmachaty@purdue.edu.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Machaty
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005306:Fertilization / Q000187:drug effects / Q000502:physiology*; D005682:Gadolinium / Q000494:pharmacology; D010063:Ovum / Q000187:drug effects / Q000378:metabolism*; D013552:Swine; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D015220:Calcium Channels; D004791:Enzyme Inhibitors; D019284:Thapsigargin; D005682:Gadolinium; D002118:Calcium
keywords: calcium; egg; fertilization; oocyte; pig; signal transduction