نتایج جستجو برای: sperm head
تعداد نتایج: 203185 فیلتر نتایج به سال:
Single structural defects involving the totality of ejaculated sperm are among rare cases of untreatable human male infertility. This form of infertility is of genetic origin and is generally transmitted as an autosomal recessive traits. Acrosome agenesis or globozoospermia results from perturbed expression of nuclear proteins or from an altered Golgi-nuclear recognition during spermiogenesis. ...
The alteration in the protein signatures of the testicular sperm during its epididymal sojourn makes it functionally competent for successful fertilization. The present study was undertaken to identify the proteins acquired on its 2 domains, that is, the head and the flagellum, during the epididymal transit using a differential proteomics approach. Testicular sperm proteome was compared with ca...
Tetramethylrhodamine-labelled microtubules were observed to move on rows of dynein arms of sea urchin sperm axonemes exposed by elastase-induced sliding disintegration. The microtubules moved towards the flagellar tip at a velocity of 3.1+/-2.1 microm second-1 (mean +/- s.d., n=53) in the presence of 0.1 mM ATP at 22 degrees C, but none moved towards the sperm head. We also examined the polarit...
We consider images of boar spermatozoa obtained with an optical phase-contrast microscope. Our goal is to automatically classify single sperm cells as acrosome-intact (class 1) or acrosome-damaged (class 2). Such classification is important for the estimation of the fertilization potential of a sperm sample for artificial insemination. We segment the sperm heads and compute a feature vector for...
Addit ion of either 25% or 50% bovine follicular fluid (FF) to Krebs Ringer phosphate buffer, with .5% fructose added (KRPF), maintained higher percentages (P<.05) of motile sperm throughout 9-hr incubation at 37 C than did 100% KRPF or 100% FF. Accelerated sperm moti l i ty and head-to-head agglutination of sperm cells were consistently observed in all diluents that contained FF. The percentag...
We consider images of boar spermatozoa obtained with an optical phase-contrast microscope. Our goal is to automatically classify single sperm cells as acrosome-intact (class 1) or acrosome-reacted (class 2). Such classification is important for the estimation of the fertilization potential of a sperm sample for artificial insemination. We segment the sperm heads and compute a feature vector for...
The salient phases of fertilization are gamete adhesion, membrane fusion, and internalization of the spermatozoon into the oocyte but the precise timeline and the molecular, membrane and cell mechanisms underlying these highly dynamical events are far from being established. The high motility of the spermatozoa and the unpredictable location of sperm/egg fusion dramatically hinder the use of re...
Phospholipase C zeta (PLCζ) is a candidate sperm-borne oocyte activating factor (SOAF) which has recently received attention as a potential biomarker of human male infertility. However, important SOAF attributes of PLCζ, including its developmental expression in mammalian spermiogenesis, its compartmentalization in sperm head perinuclear theca (PT) and its release into the ooplasm during fertil...
BACKGROUND Sperm-oocyte fusion is a critical step in fertilization, which requires a series of proteins from both spermatozoa and oocyte to mediate membrane adhesion and subsequent fusion. A rat spermatozoa membrane protein is endoplasmic reticulum protein 29 (ERp29), which significantly increases on the sperm surface as well as in the cytoplasm of epididymal epithelia from caput to cauda as th...
OBJECTIVE Sperm morphology plays an important role in infertility, especially in cases of defects in the heads of spermatozoa. Tapered-head or elongated-head spermatozoa are examples of morphological abnormalities. The aim of this study was to compare the semen parameters, levels of protamine deficiency, and frequency of apoptosis between patients with normozoospermia and those with teratozoosp...
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