How Pig Sperm Prepares to Fertilize: Stable Acrosome Docking to the Plasma Membrane
نویسندگان
چکیده
BACKGROUND Mammalian sperms are activated in the oviduct. This process, which involves extensive sperm surface remodelling, is required for fertilization and can be mimicked under in vitro fertilization conditions (IVF). METHODOLOGY/PRINCIPAL FINDINGS Here we demonstrate that such treatments caused stable docking and priming of the acrosome membrane to the apical sperm head surface without the emergence of exocytotic membrane fusion. The interacting membranes could be isolated as bilamellar membrane structures after cell disruption. These membrane structures as well as whole capacitated sperm contained stable ternary trans-SNARE complexes that were composed of VAMP 3 and syntaxin 1B from the plasma membrane and SNAP 23 from the acrosomal membrane. This trans-SNARE complex was not observed in control sperm. CONCLUSIONS/SIGNIFICANCE We propose that this capacitation driven membrane docking and stability thereof is a preparative step prior to the multipoint membrane fusions characteristic for the acrosome reaction induced by sperm-zona binding. Thus, sperm can be considered a valuable model for studying exocytosis.
منابع مشابه
Fertilization with acrosome-reacted mouse sperm: implications for the site of exocytosis.
F or successful mammalian fertilization, sperm penetrate the outer investments of female gametes in the ampulla of the oviduct and fuse with the egg plasma membrane. The “fertilizing” sperm traverse the cumulus mass surrounding ovulated eggs, bind temporarily, and then penetrate through the zona pellucida, a structured extracellular glycomatrix, to enter into the perivitelline space (Fig. 1A). ...
متن کاملExpression of Syntaxin 2 in Bovine Sperm.
Syntaxins are membrane integrated Q-SNARE proteins known to participate in exocytosis. Vesicle docking involves the binding of two plasma membrane proteins, syntaxin and SNAP-25, to the vesicle membrane protein VAMP to form a stable trimeric core complex; synaptophysin is thought to regulate the formation of this complex. Although the members of Q-SNARE proteins are characterized in somatic cel...
متن کاملSperm head membrane reorganisation during capacitation.
The sperm cell has a characteristic polarized morphology and its surface is also highly differentiated into different membrane domains. Junctional protein ring structures seal the surface of the mid-piece from the head and the tail respectively and probably prevent random diffusion of membrane molecules over the protein rings. Despite the absence of such lateral diffusion-preventing structures,...
متن کاملCapacitation as a regulatory event that primes spermatozoa for the acrosome reaction and fertilization.
Capacitation is defined as the series of transformations that spermatozoa normally undergo during their migration through the female genital tract, in order to reach and bind to the zona pellucida, undergo the acrosome reaction, and fertilize the egg. During this process, extensive changes occur in all sperm compartments (head and flagellum; membrane, cytosol, cytoskeleton), factors originating...
متن کاملSPERM MEMBRANE CHANNELS, RECEPTORS AND KINEMATICS : Using boar spermatozoa for drug toxicity screening
.............................................................................................................................. I POPULÄRVETENSKAPLIG SAMMANFATTNING ........................................................... II LIST OF PAPERS .................................................................................................................... V ABBREVIATIONS .........................
متن کامل