Heat shock protein 70 (HSP70) is part of a superfamily of molecular chaperones, which protect cells from chemical and heat shock. The objectives of this study were to determine the presence of HSP70 in bovine spermatozoa and its subcellular localization during different stages of spermatogenesis. Analysis of sperm proteins by Western blotting using a monoclonal antibody to the inducible form of...

As the number of spermatozoal characters being described in reptiles increases, it is important to detail the ontogeny of the features leading to the mature morphology of the spermatozoa which may give rise to more comprehensive data matrices for future phylogenetic analyses within the Reptilia. Therefore, spermiogenically active testes from Anolis lineatopus were investigated ultrastructurally...

To fuse with oocytes, spermatozoa of eutherian mammals must pass through extracellular coats, the cumulus cell layer, and the zona pellucida (ZP). It is generally believed that the acrosome reaction (AR) of spermatozoa, essential for zona penetration and fusion with oocytes, is triggered by sperm contact with the zona pellucida. Therefore, in most previous studies of sperm-oocyte interactions i...

Zona pellucida protein 3, a protein of the egg's extracellular matrix, and progesterone secreted by granulosa cells surrounding the oocyte are regarded as physiological stimuli of sperm acrosome reaction. Signal transduction steps initiated by both stimuli result in influx of Ca2+ from the extracellular space. Herein, we propose a role for prostaglandin (PG) E as a physiological inducer of Ca2+...

The role of cAMP in spermatic functions was classically thought to be mediated exclusively through the activation of Protein Kinase A (PKA). However, it has recently been shown that cAMP also exerts its effects through a PKA-independent pathway activating a family of proteins known as Epac proteins. Therefore, many of the spermatic functions thought to be regulated by cAMP through the activatio...

In vitro supplementation with date seed oil (DSO) can protect spermatozoa against hydrogen peroxide (H2O2)-mediated damage and can improve sperm function, possibly owing to antioxidant properties. We tested the antioxidant effects of DSO on human sperm motility, sperm viability, reacted acrosome and lipid peroxidation assessed in vitro after H2O2-mediated oxidative damage in spermatozoa. Sixtee...

BACKGROUND Acrosome formation and nuclear shaping are the main events in spermatogenesis. During spermiogenesis in Exopalaemon modestus, a unique microtubular structure called the acroframosome (AFS) forms in spermatids. The AFS links to a temporary organelle called the lamellar complex (LCx) leading to the formation of an everted umbrella-shaped acrosome and a dish-shaped nucleus in the mature...

Protein recycling is important for maintaining homeostasis of the Golgi and its cisternae. The Vps54 (Scat) protein, a subunit of the GARP tethering complex, is a central factor in retrograde transport to the trans-Golgi. We found the scat(1) mutant to be male sterile in Drosophila with individualization problems occurring during spermatogenesis. Another typically observed phenotype was the abn...

To date multiple studies exist that examine the morphology of spermatozoa. However, there are limited numbers of data detailing the ontogenic characters of spermiogenesis within squamates. Testicular tissues were collected from Cottonmouths (Agkistrodon piscivorus) and tissues from spermiogenically active months were analyzed ultrastructurally to detail the cellular changes that occur during sp...

BACKGROUND This prospective study compared the acrosome reaction following ionophore challenge (ARIC) versus conventional sperm parameters and sperm velocities in predicting successful outcome following ovarian stimulation and intrauterine insemination. METHODS All patients were offered a maximum of three treatment cycles. Conventional semen analysis was performed and sperm velocities were me...