نتایج جستجو برای: sperm

تعداد نتایج: 36738  

2015
Sheri Skerget Matthew A. Rosenow Konstantinos Petritis Timothy L. Karr Jay M. Baltz

In mammals, transit through the epididymis, which involves the acquisition, loss and modification of proteins, is required to confer motility and fertilization competency to sperm. The overall dynamics of maturation is poorly understood, and a systems level understanding of the complex maturation process will provide valuable new information about changes occurring during epididymal transport. ...

Journal: :Human reproduction 2007
Nabil Aziz Tamer Said Uwe Paasch Ashok Agarwal

BACKGROUND This study aimed to assess the relationship between apoptosis in human ejaculated spermatozoa, sperm morphology and the novel sperm deformity index (SDI). METHODS Semen specimens from 50 healthy donors were prepared by density-gradient centrifugation followed by incubating the prepared sperm with paramagnetic annexin V-conjugated microbeads and subjecting this to magnetic cell sort...

Journal: :Fertility and sterility 2005
Attila Jakab Denny Sakkas Elena Delpiano Sevil Cayli Ertug Kovanci David Ward Alberto Revelli Gabor Huszar

OBJECTIVE To test a newly invented intracytoplasmic sperm injection (ICSI) sperm selection method based on sperm hyaluronic acid (HA) binding. DESIGN Comparison of chromosomal disomy and diploidy frequencies in sperm arising from semen and in HA-bound sperm. SETTING Academic andrology laboratory. PATIENT(S) Men presenting for semen analysis. INTERVENTION(S) Washed sperm fractions of 32 ...

Journal: :Proceedings. Biological sciences 2016
Javier delBarco-Trillo Olga García-Álvarez Ana Josefa Soler Maximiliano Tourmente José Julián Garde Eduardo R S Roldan

Sperm competition, a prevalent evolutionary process in which the spermatozoa of two or more males compete for the fertilization of the same ovum, leads to morphological and physiological adaptations, including increases in energetic metabolism that may serve to propel sperm faster but that may have negative effects on DNA integrity. Sperm DNA damage is associated with reduced rates of fertiliza...

2016
Ming-Wen Li Olivia C Glass Jasmin Zarrabi Lisa N. Baker K. C. Kent Lloyd

Different protocols incorporating methyl-β-cyclodextrin (MBCD) and reduced glutathione (GSH) have been reported to improve IVF recovery of cryopreserved mouse sperm on a C57BL/6 (J and N) genetic background. However, it is not clear which IVF protocol is most appropriate when using the various methods to cryorecover sperm with different sperm quality and sample volumes. Therefore, in the presen...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Lukas Schärer D Timothy J Littlewood Andrea Waeschenbach Wataru Yoshida Dita B Vizoso

Sperm are the most diverse of all animal cell types, and much of the diversity in sperm design is thought to reflect adaptations to the highly variable conditions under which sperm function and compete to achieve fertilization. Recent work has shown that these conditions often evolve rapidly as a consequence of multiple mating, suggesting a role for sexual selection and sexual conflict in the e...

Journal: :Journal of andrology 2010
Artay Yagci William Murk Jill Stronk Gabor Huszar

During human spermiogenesis, the elongated spermatids undergo a plasma membrane remodeling step that facilitates formation of the zona pellucida and hyaluronic acid (HA) binding sites. Various biochemical sperm markers indicated that human sperm bound to HA exhibit attributes similar to that of zona pellucida-bound sperm, including minimal DNA fragmentation, normal shape, and low frequency of c...

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...

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