CatSper channels in sea urchin sperm

Cell Calcium. 2021 Nov:99:102466. doi: 10.1016/j.ceca.2021.102466. Epub 2021 Aug 31.

Abstract

Sea urchin sperm swimming is regulated by speract, a decapeptide released from egg jelly that induces chemotaxis and triggers membrane potential (Em) changes, intracellular increases in cyclic nucleotides (cGMP, cAMP), pH (pHi) and calcium concentration ([Ca2+]i). The identity of the ionic transporters associated with the [Ca2+]i changes required for chemotaxis is not fully known. CatSper, a sperm exclusive Ca2+ channel has been detected by proteomic analysis and immunofluorescence in sea urchin sperm and there is evidence for its involvement in chemotaxis. This work presents an electrophysiological characterization of a CatSper channel in sea urchin sperm. By swelling sperm suspending them in 10-fold diluted artificial sea water (ASW) we achieve on-cell patch-clamp recordings that document a mildly voltage and pHi dependent Na+ permeable channel (in absence of divalent ions in the pipette), sensitive to speract, and blocked by Mibefradil (Mibe), NNC55-0396 (NNC) and RU1968 (RU) resembling CatSper. We also recorded a voltage dependent Cl- channel inhibited by Niflumic Acid and the TMEM16A blocker.

Keywords: Calcium; CatSper; Patch-clamp; Sea urchin; Sperm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium Channels
  • Male
  • Proteomics*
  • Sea Urchins / metabolism
  • Sperm Motility*
  • Spermatozoa / metabolism

Substances

  • Calcium Channels
  • Calcium