nderstanding reproduction impacts not only human physiology and health, but also livestock and fishing. The dialogue between gametes is key for fertilization to occur and involves the regulation of their ionic permeability. Ionic channels play an important role in the motility, maturation, and induction of sperm acrosomal reaction (RA). The sperm is a subject of renewed interest in cell physiology due to its fundamental function. Understanding the parameters that affect your mobility is key to understanding how fertilization occurs. The gelatin layer surrounding the sea urchin ovum Strongylocentrotus purpuratuscontains speract, a decapeptide that modulates sperm motility. It is now accepted that binding of speract to its receptor (s) activates a guanylate cyclase (GC) transiently. The increase in cGMP activates cGMP-regulated K + channels that make the membrane potential (Em) of the sperm more negative. This temporary hyperpolarization stimulates: a Na + / Ca2 + exchanger that keeps the intracellular concentration of Ca2 + ([Ca2 +] i) low, a Na + / H + exchange, adenylate cyclase (AC) and possibly a cation channel called SpHCN. Subsequently, the Em is repolarized and then depolarized resulting in increases in: intracellular pH (pHi), [Ca2 +] i, cAMP and [Na +] i. [Ca2 +] i is known to be closely related to the way in which it flogs the scourge.
Universidad Nacional Autónoma de México
Web Page: http://www.ibt.unam.mx/server/PRG.base?tipo:doc,dir:PRG.grupo,par:Gad,tit:_Grupo_del__Dr._Alberto_Darszon