A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long-range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. W...

AIM To simultaneously determine the localization of histones and protamines within human sperm nuclei. METHODS Immunofluorescence of the core histones and protamines and fluorescence in situ hybridization of the telomere region of chromosome 16 was assessed in decondensed human sperm nuclei. RESULTS Immunofluorescent localization of histones, protamine 1 (PRM1) and protamine 2 (PRM2) along ...

background: in previous investigations, it has been clarified that electromagnetic fields (elf) can cause some changes in cellular behavior. the aim of this prospective study was to investigate the effect of magnetic field (mf) on human sperm parameters of motility, morphology, and viability. materials and methods: semen samples were collected from 12 fertile men, and were allowed to liquefy fo...

Objective To investigate effects of cryopreservation on changes of the ultrastructure of human testicular sperm and evaluate the efficacy of cryopreserving testicular tissue as a source of sperm for assisted reproduction. Methods Testicular biopsy tissues were obtained from infertile patients (n=12) with obstructive azoospermia and cryopreserved. Testicular sperm motility was observed after in ...

PURPOSE We review the history of the cryopreservation of human sperm. The current methods of cryopreservation and indications are highlighted, and the success rates of the various uses of cryopreserved sperm are reviewed. Potential adverse sequelae of human cryopreservation are also discussed. MATERIALS AND METHODS Indications for cryopreservation include several applications, namely homologo...

GRP78, a resident endoplasmic reticulum (ER) chaperone involved in protein transport, folding and assembly, has been reported in sperm. It is shown to be localized in the neck region of human sperm. We have previously reported GRP78 to be less phosphorylated in asthenozoosperm.The present study aimed to determine whether sperm GRP78 undergoes phosphorylation changes during epididymal maturation...

Sperm capacitation is a complex and indispensable physiological process that spermatozoa must undergo in order to acquire fertilization capability. Spermatozoa from several mammalian species, including mice, exhibit a capacitation-associated plasma membrane hyperpolarization, which is necessary for the acrosome reaction to occur. Despite its importance, this hyperpolarization event has not been...

A D-mannosylated albumin (DMA) neoglycoprotein was assessed to validate experimentally a probe capable of detecting mannose-binding sperm receptors involved in human sperm-egg interaction. DMA specifically blocked zona binding of swim-up human spermatozoa in a concentration-dependent manner. While no considerable effect was observed on sperm-zona initial contact, almost 50% of spermatozoa bound...

CatSper channel has been considered the principal sperm Ca2+ channel responsible for the cytosolic Ca2+ elevation required for various sperm functions necessary for fertilization [1-4]. However, the mechanism underlying the activation of CatSper channel by various physiological ligands remain incompletely understood. We have recently demonstrated the expression of C-C chemokine receptor 6 (CCR6...

There are few reports on the role of protein phosphatases during capacitation. Here, we report on the role of PP2B, PP1, and PP2A during human sperm capacitation. Motile sperm were resuspended in non-capacitating medium (NCM, Tyrode's medium, albumin- and bicarbonate-free) or in reconstituted medium (RCM, NCM plus 2.6% albumin/25 mM bicarbonate). The presence of the phosphatases was evaluated b...