18 This work describes the morphology of the sperm cell of Maja brachydactyla, with emphasis on 19 localizing actin and tubulin. The spermatozoon of M. brachydactyla is similar in appearance and 20 organization to other brachyuran spermatozoa. The spermatozoon is a globular cell composed of 21 a central acrosome, which is surrounded by a thin layer of cytoplasm, and a cup-shaped nucleus 22 with...

Fertilization typically involves membrane fusion between sperm and eggs. In Drosophila, however, sperm enter eggs with membranes intact. Consequently, sperm plasma membrane breakdown (PMBD) and subsequent events of sperm activation occur in the egg cytoplasm. We previously proposed that mutations in the sneaky (snky) gene result in male sterility due to failure in PMBD. Here we support this pro...

Acrosomal exocytosis in mammalian spermatozoa is a process essential for fertilization. We report here that atrial natriuretic peptide (ANP) markedly stimulates acrosomal exocytosis of capacitated human spermatozoa. Typically, ANP exerts some of its actions via activation of the ANP receptor (ANPR-A), a particulate guanylyl cyclase-linked receptor, and subsequent formation of guanosine 3',5'-cy...

During the last phase of spermatogenesis, spermiogenesis, haploid round spermatids metamorphose towards spermatozoa. Extensive cytoplasmic reduction and chromatin remodelling together allow a dramatic decrease of cellular, notably nuclear volume. DNA packing by a nucleosome based chromatin structure is largely replaced by a protamine based one. At the cytoplasmic level among others the acrosome...

Carbohydrates are candidates for the basis of species-selective interaction of gametes during mammalian fertilization. In this study, we sought to clarify the roles of sugar residues in the species-selective, sperm-oocyte interaction in pigs and cattle. Acrosome-intact porcine and bovine sperm exhibited their strongest binding affinities for β-Gal and α-Man residues, respectively. Porcine-sperm...

Freezing and thawing processes result in production accumulation of high concentrations reactive oxygen species that are detrimental to spermatozoal motility fertility. Therefore, supplementation exogenous source antioxidants freezing diluent is crucial. The aim the present study was investigate for first time whether semen with alpha linolenic acid (ALA) can improve motility, viability, membra...

This study's goal was to reveal the effects of antioxidant supplementation on motility, motion characters, morphology, DNA integrity, and fertilizing potential cryopreserved bovine sperm. The ejaculates were collected from three Holstein bulls. At least ten per bull. immediately separated into five aliquots, diluted in Cryobos (Magapor Co. Ltd., Zaragoza, Spain) commercial extender, including 2...

MicroRNAs (miRNAs) are a class of short non-coding RNA molecules, which diversely regulate gene expression in organisms. Although the regulatory role of these small RNA molecules has been recently explored in animal spermatogenesis, the role of miR-124 in male germ cells is poorly defined. In our previous study, flotillin-2 was investigated as a novel Golgi-related protein involved in sperm acr...

To elucidate the molecular mechanisms involved in sperm maturation during epididymal transit, we intended to isolate secretory molecules that are region-specifically expressed along the epididymis and secreted into the lumen of epididymal ducts. By using differential display screening and DNA sequence analyses, we isolated a rat bactericidal/permeability-increasing protein (BPI) possessing a si...

Soluble N-ethylmalameide-sensitive factor attachment protein receptor (SNARE) proteins are present in mammalian sperm and could be involved in critical membrane fusion events during fertilization, namely the acrosome reaction. Vesicle-associated membrane protein/synaptobrevin, a SNARE on the membrane of a vesicular carrier, and syntaxin 1, a SNARE on the target membrane, as well as the calcium ...