What does a Common Channel for Electrolytes and Non-electrolytes in the Sperm Mean?

Cell volume is central to osmoregulation in intact cells. Bovine spermatozoa, as also other mammalian spermatozoa, exhibit a very rapid regulatory volume decrease (RVD) when exposed to hypotonic saline media. This response, fastest known in animal cells, is mediated by a putative potassium channel which the pharmacological properties of a conventional channel and yet admits both electrolytes and non-electrolytes. The evolutionary basis and functional role of this conserved quinine-sensitive channel in mammalian sperm could offer hitherto unexplored facets of the link(s) between ecology and reproduction.