title: Sperm-activating peptide induces asymmetric flagellar bending in sea urchin sperm.
abstract: Speract, a sperm-activating peptide (SAP) from sea urchin eggs, induces various sperm responses including a transient increase in the intracellular Ca2+ concentration. However, it has not been clarified how speract modulates sperm motility and whether it functions as a chemoattractant. To confirm the effect of speract on sperm motility, we observed the flagellar bending response to speract in sperm of Hemicentrotus pulcherrimus, in experiments using caged speract and a lighting system for a microscope newly developed with a power LED. We found that speract induces increases in curvature of swimming paths and changes flagellar bending shape to asymmetric. These facts show that speract directly regulates flagellar motility, and suggest that speract-induced increases in intracellular Ca2+ concentration play an actual role in regulation of the flagellar movement.
authors.affiliation: Department of Advanced Biosciences, Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan.
authors.forename: Kogiku
authors.initials: K
authors.lastname: Shiba
authors.forename: Junko
authors.initials: J
authors.lastname: Ohmuro
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Mogami
authors.forename: Takuya
authors.initials: T
authors.lastname: Nishigaki
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Wood
authors.forename: Alberto
authors.initials: A
authors.lastname: Darszon
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Tatsu
authors.forename: Noboru
authors.initials: N
authors.lastname: Yumoto
authors.forename: Shoji A
authors.initials: SA
authors.lastname: Baba
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D047330:Hemicentrotus / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009842:Oligopeptides / Q000378:metabolism* / Q000494:pharmacology; D013081:Sperm Motility / Q000187:drug effects* / Q000502:physiology; D013082:Sperm Tail / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D013997:Time Factors; D014741:Video Recording
chemical_list: D009842:Oligopeptides; C028364:speract; D002118:Calcium