نتایج جستجو برای: sperm coating

تعداد نتایج: 73758  

2017
MD Anisuzzaman Mondal Yuji Takagi Shoji A. Baba Koh‐ichi Hamano

Aim To examine the potential of bovine follicular fluid (BFF) to attract bull spermatozoa. Methods The ability of the BFF to attract bull sperm was evaluated by observing changes in sperm migration after being placed in a cross-column chamber. The movement parameters of the heads and flagella of the sperm that were attracted to the BFF were analyzed by using the Computer Assisted Sperm Analys...

Journal: :Human reproduction 2003
De Yi Liu H W Gordon Baker

BACKGROUND The frequency of defective sperm-zona pellucida (ZP) interaction in teratozoospermic infertile men was investigated. METHODS Sperm-ZP binding and the ZP-induced acrosome reaction (ZPIAR) were performed in 125 infertile men with <5% of their sperm with normal morphology (strict criteria), but with a sperm count > or =20x10(6)/ml and total motility >30% in semen. Oocytes that failed ...

Journal: :Evolution; international journal of organic evolution 2009
Stefan Lüpold George M Linz James W Rivers David F Westneat Tim R Birkhead

Sperm morphology varies considerably across taxa, and postcopulatory sexual selection is thought to be one of the main forces responsible for this diversity. Several studies have investigated the effects of the variation in sperm design on sperm function, but the consequences of variation in sperm design on testis morphology have been overlooked. Testes size or architecture may determine the si...

2013
Kazuya Takahashi Kazuhiro Kikuchi Yasuomi Uchida Saeko Kanai-Kitayama Reiichiro Suzuki Reiko Sato Kazunori Toma Masaya Geshi Satoshi Akagi Minoru Nakano Naoto Yonezawa

Carbohydrates are candidates for the basis of species-selective interaction of gametes during mammalian fertilization. In this study, we sought to clarify the roles of sugar residues in the species-selective, sperm-oocyte interaction in pigs and cattle. Acrosome-intact porcine and bovine sperm exhibited their strongest binding affinities for β-Gal and α-Man residues, respectively. Porcine-sperm...

Journal: :Fertility and sterility 1997
R K Sharma O F Padron A J Thomas A Agarwal

OBJECTIVE To identify whether the cause, site of ductal obstruction, and characteristics of fluid aspirates are associated with the cryosurvival and fertility after thawing of sperm obtained during reconstruction of the excurrent ducts with microsurgical epididymal sperm aspiration, vasal sperm aspiration, or both. DESIGN Prospective study. SETTING Andrology center at a tertiary care instit...

Journal: :Biology Letters 2006

2012
Dhana Rajan

The present study to investigate that the correlation between sperm parameters and sperm DNA fragmentation in fertile and infertile cigarette smoking patient. Forty men undergoing infertility evaluation were divided into four groups according their smoking ability (A: 2 days ( n=10), B: 4 days ( n=10), C: 8 days ( n=10), D: 15 days ( n=10)) sperm parameters ( sperm concentration, pH, Viscosity,...

Journal: :Developmental dynamics : an official publication of the American Association of Anatomists 2007
Liana B Lamont Judith Kimble

The specification of a germ cell as sperm or oocyte and determination of cell number remain unsolved questions in developmental biology. This paper examines Caenorhabditis elegans FOG-1, a CPEB-related RNA-binding protein that controls the sperm fate. We find that abundant FOG-1 protein is observed transiently in germ cells just prior to their expression of an early sperm-differentiation marker...

2015
Bruno Camargo Tiseo Russell Paul Hayden Cigdem Tanrikut

Nonobstructive azoospermia (NOA) is characterized by the complete absence of sperm in the ejaculate due to testicular failure. The evaluation and management of patients with NOA offer a challenge to the reproductive urologist. In the era of in vitro fertilization with intracytoplasmic sperm injection, surgical sperm extraction techniques can afford men with NOA biologic paternity. To provide a ...

Journal: :Current Biology 2003
D. J. Hosken

Although sperm are typically thought to be small, tadpole-like cells produced in vast quantities, sperm size, form and number all vary tremendously across species. Sperm form ranges from amoeboid or discoid to multiflagellate elongated structures [1]. Even within the more familiar uniflagellate spermatozoa, length varies by several orders of magnitude, from the tiny 28μm long porcupine sperm to...

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