title: Calcium channels in chicken sperm regulate motility and the acrosome reaction.
abstract: Intracellular cytoplasmic calcium ([Ca(2+) ]i ) has an important regulatory role in gamete functions. However, the biochemical components involved in Ca(2+) transport are still unknown in birds, an animal class that has lost functional sperm-specific CatSper channels. Here, we provide evidence for the presence and expression of various Ca(2+) channels in chicken sperm, including high voltage-activated channels (L and R types), the store-operated Ca(2+) channel (SOC) component Orai1, the transient receptor potential channel (TRPC1) and inositol-1,4,5-trisphosphate receptors (IP3 R1). L- and R-type channels were mainly localized in the acrosome and the midpiece, and T-type channels were not detected in chicken sperm. Orai1 was found in all compartments, but with a weak, diffuse signal in the flagellum. TRCP1 was mainly localized in the acrosome and the midpiece, but a weak diffuse signal was also observed in the nucleus and the flagellum. IP3 R1 was mainly detected in the nucleus. The L-type channel inhibitor nifedipine, the R-type channel inhibitor SNX-482 and the SOC inhibitors MRS-1845, 2-APB and YM-58483 decreased [Ca(2+) ]i sperm motility and acrosome reaction capability, with the SOC inhibitors inhibiting these functions most efficiently. Furthermore, we showed that Ca(2+) -mediated induction of AMP-activated protein kinase (AMPK) phosphorylation was blocked by SOC inhibition. Our identification of important regulators of Ca(2+) signaling in avian sperm suggests that SOCs play a predominant role in gamete function, whereas T-type channels may not be involved. In addition, Ca(2+) entry via SOCs appears to be the most likely pathway for AMPK activation and energy-requiring sperm functions such as motility and the acrosome reaction.
authors.affiliation: Institut National de la Recherche Agronomique, UMR 85, Physiologie de la Reproduction et des Comportements, Nouzilly, France.|Centre National de la Recherche Scientifique, UMR 7247, Nouzilly, France.|Université François Rabelais de Tours, Tours, France.|Faculty of Biology-Agricultural Engineering, Quy Nhon University, Quy Nhon, Vietnam.
authors.forename: Thi Mong Diep
authors.initials: TM
authors.lastname: Nguyen
authors.affiliation: Institut National de la Recherche Agronomique, UMR 85, Physiologie de la Reproduction et des Comportements, Nouzilly, France.|Centre National de la Recherche Scientifique, UMR 7247, Nouzilly, France.|Université François Rabelais de Tours, Tours, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Duittoz
authors.affiliation: Institut National de la Recherche Agronomique, UR083 Recherches Avicoles, Nouzilly, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Praud
authors.affiliation: Institut National de la Recherche Agronomique, UMR 85, Physiologie de la Reproduction et des Comportements, Nouzilly, France.|Centre National de la Recherche Scientifique, UMR 7247, Nouzilly, France.|Université François Rabelais de Tours, Tours, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Combarnous
authors.affiliation: Institut National de la Recherche Agronomique, UMR 85, Physiologie de la Reproduction et des Comportements, Nouzilly, France.|Centre National de la Recherche Scientifique, UMR 7247, Nouzilly, France.|Université François Rabelais de Tours, Tours, France.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Blesbois
mesh_terms: D020101:Acrosome Reaction / Q000502:physiology*; D000263:Adenylate Kinase / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D002645:Chickens; D008297:Male; D013081:Sperm Motility / Q000502:physiology*
chemical_list: D015220:Calcium Channels; D000263:Adenylate Kinase; D002118:Calcium
keywords: calcium channels; chicken sperm