Using homologous recombination, we have previously produced male mice carrying a disruptive mutation (Acr-/-) in the acrosin gene. Although Acr-/- mouse sperm lacking the acrosin protease activity still penetrated the zona pellucida and fertilized the egg, the mutant sperm exhibited a delay in penetration of the zona pellucida solely at the early stages after insemination. To further elucidate ...

The efficiency of sperm capacitation and of the acrosome reaction was studied in the teratospermic domestic cat to evaluate further the etiology of compromised zona pellucida penetration and oocyte fertilization. Specific objectives were to compare normospermic and teratospermic cat ejaculates for 1) the kinetics and timing of sperm capacitation in vitro as determined by an ionophore-induced ac...

BACKGROUND In rodents, the cell surface complement regulatory protein CD46 is expressed solely on the spermatozoal acrosome membrane. Ablation of the CD46 gene is associated with a faster acrosome reaction. Sperm from Apodemus flavicollis (yellow-necked field mice), A. microps (pygmy field mice) and A. sylvaticus (European wood mice) fail to express CD46 protein and exhibit a more rapid acrosom...

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...

BACKGROUND The presence of small membranous particles characterizes the male genital fluids of different mammalian species. The influence of semen vesicles, denominated prostasomes, on sperm functional properties has been well documented in humans, but their biological activity is scarcely known in other species. The present work investigated prostasome-like vesicles in pig semen for their abil...

The extracellular coat, or zona pellucida, of mammalian eggs contains species-specific receptors to which sperm bind as a prelude to fertilization. In mice, ZP3, one of only three zona pellucida glycoproteins, serves as sperm receptor. Acrosome-intact, but not acrosome-reacted, mouse sperm recognize and interact with specific O-linked oligosaccharides of ZP3 resulting in sperm-egg binding. Bind...

OBJECTIVE To investigate the role of the cumulus cells and the cumulus matrix in affecting the penetrability, morphology, acrosome reaction, and motility of human spermatozoa penetrating the cumulus oophorus. DESIGN Controlled experimental laboratory study. SETTING University gynecology unit. PATIENT(S) Women undergoing assisted reproduction treatment and men visiting the subfertility cli...

Mammalian spermatozoa undergo capacitation and acrosome reaction in order to fertilize the egg. The PKC-ERK1/2 pathway plays an important role in human spermatozoa motility, capacitation and the acrosome reaction. Here we demonstrate that ERK1/2 phosphorylates proAKAP4 on Thr265 in human spermatozoa in vitro and in vivo. Cyclic AMP (cAMP) had no effect on ERK1/2 activity in human spermatozoa, b...

The aim of this work was to study the influence of vitamin E (2mM) on capacitation and acrosome reaction of crossbred cattle bull spermatozoa. Fresh semen suspended in TALP medium (pH 7.4) was divided into four equal fractions. All fractions; control (containing TALP + spermatozoa) and the experimental [treated / untreated with ferrous ascorbate (FeAA – 150 μM FeSO4 : 750 μM ascorbic acid); sup...