Spermatozoa are stored in a quiescent state in the male reproductive tract and motility is induced in response to various environmental stimuli, such as change of osmolality (general case) and a decrease of extracellular K+ in fish from Acipenseridae family. This study was aimed to investigate the relationship between osmolality and extracellular K+ concentration in controlling sperm motility in sturgeon. Pre-incubation of sturgeon sperm for 5s in hypertonic solutions of glycerol, NaCl, or sucrose (each of 335 mOsm/kg osmolality) prepares sturgeon spermatozoa to become fully motile in presence of high concentration of K+ ions (15 mM), which has previously been demonstrated to fully repress motility. Furthermore, presence of 0.5mM KCl during the high osmolality pre-incubation exposure completely prevented subsequent spermatozoa activation in a K+-rich media. Manipulating the transport of K+ ions by the presence of K+ ionophore (valinomycin), it was concluded that once an efflux of K+ ions, the precursor of sturgeon sperm motility activation, is taking place, spermatozoa then become insensitive to a large extracellular K+ concentration.

University of South Bohemia in Ceske Budejovice Faculty of Fisheries and Protection of Waters South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Research Institute of Fish Culture and Hydrobiology Zatisi 728 2 Vodnany 389 25 Czech Republic

Citace poskytuje Crossref.org

Egg-sperm interaction in sturgeon: role of ovarian fluid

Influence of Environmental Temperature and Hormonal Stimulation on the In Vitro Sperm Maturation in Sterlet Acipenser ruthenus in Advance of the Spawning Season