نتایج جستجو برای: sperm head vacuole

تعداد نتایج: 213756  

2012
Mahmoud Aarabi Yang Yu Wei Xu Man Y. Tse Stephen C. Pang Young-Joo Yi Peter Sutovsky Richard Oko

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...

2010
Xiaoqian Ying Yue Liu Qiangsu Guo Fei Qu Wei Guo Yemin Zhu Zhide Ding

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...

2017
Fatemeh Dehghanpour Nasim Tabibnejad Farzaneh Fesahat Fatemeh Yazdinejad Ali Reza Talebi

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...

Journal: :Nature Communications 2021

Abstract Reproductive success depends on efficient sperm movement driven by axonemal dynein-mediated microtubule sliding. Models predict sliding at the base of tail – centriole but such has never been observed. Centrioles are ancient organelles with a conserved architecture; their rigidity is thought to restrict Here, we show that, in mammalian sperm, atypical distal (DC) and its surrounding pe...

Journal: :Reproduction 2005
A Cesari M R Katunar M A Monclus A Vincenti J C de Rosas M W Fornés

Bovine sperm protease, 66 kDa (BSp66) is a serine protease previously characterized in bovine spermatozoa. Like other proteases, it may be present in sperm from other mammalian species different from bovine, playing a role in the fertilization process. In this study, we looked for BSp66 in hamster spermatozoa using heterologous antibodies against bovine BSp66. An immunoreactive protein was dete...

Journal: :Reviews of reproduction 2000
C P Blobel

Fertilin is a sperm surface protein with an essential role in fertilization. It is required for the migration of spermatozoa through the oviduct, for binding to the zona pellucida, and for efficient binding to the egg plasma membrane. Fertilin consists of two subunits, fertilin alpha and beta, both of which belong to the metalloprotease-disintegrin protein family (ADAMs). Fertilin alpha and bet...

2011
Sara Calhim Michael C. Double Nicolas Margraf Tim R. Birkhead Andrew Cockburn

Postcopulatory sexual selection is an important force in the evolution of reproductive traits, including sperm morphology. In birds, sperm morphology is known to be highly heritable and largely condition-independent. Theory predicts, and recent comparative work corroborates, that strong selection in such traits reduces intraspecific phenotypic variation. Here we show that some variation can be ...

Journal: :Fertility and sterility 2008
Guruprasad Kalthur Satish Kumar Adiga Dinesh Upadhya Satish Rao Pratap Kumar

OBJECTIVE To test whether sperm with abnormal head morphology are more likely to undergo DNA damage and/or chromatin modification during the process of freeze-thawing. DESIGN In this prospective study, the semen samples from forty-four men attending the infertility clinic were included. Samples were divided into aliquots to allow direct comparison of fresh and frozen spermatozoa from the same...

Journal: :The Journal of Cell Biology 1975
P S Ecklund L Levine

Mouse sperm were labeled in vivo with [3H]arginine. The sperm were then followed autoradiographically from the time of label incorporation until after fertilization. The label was completely lost from the sperm head after fertilization, during the oocyte's second meiotic division. That the [3H]arginine was incorporated into a sperm-specific basic protein was demonstrated by fractionating acid e...

Journal: :The Onderstepoort journal of veterinary research 1994
J T Soley D C Roberts

The three-dimensional structure and size of ostrich sperm is unknown. In this study, the morphology and dimensions of ostrich sperm were determined by scanning electron microscopy of semen samples obtained from sexually mature males during the breeding season. The results indicate that sperm cells of the ostrich are of the sauropsid type characteristic of non-passerine birds and, in general app...

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