نتایج جستجو برای: sperm

تعداد نتایج: 36738  

Journal: :The FASEB Journal 2021

Sperm acquire the ability to fertilize in a process called capacitation and undergo hyperactivation, change motility pattern, which depends on Ca2+ transport by CatSper channels. is essential for fertilization it subjected complex regulation that not fully understood. Here, we report similar CatSper, Cdc42 distribution principal piece confined four linear domains this localization disrupted Cat...

Journal: :Molecular human reproduction 2014
John L Fitzpatrick Stefan Lüpold

Sperm experience intense and varied selection that dramatically impacts the evolution of sperm quality. Selection acts to ensure that sperm are fertilization-competent and able to overcome the many challenges experienced on their way towards eggs. However, simply being able to fertilize an egg is not enough to ensure male fertility in most species. Owing to the prevalence of female multiple mat...

2013
Oliver Vöcking Gabriele Uhl Peter Michalik

Storage of sperm inside the female genital tract is an integral phase of reproduction in many animal species. The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. Here, we focus on sperm activation in...

2017
Kohei UMEZU Yuuki HIRADATE Takashi NUMABE Kenshiro HARA Kentaro TANEMURA

Sperm sorting by flow cytometry is a useful technology in the bovine industry, but the conception rates after artificial insemination using sex-sorted sperm are lower than when using the un-sorted sperm. In this study, we have investigated the causes for these low conception rates. We have focused on changes caused by flow cytometry to the glycocalyx, which forms the outermost surface of the sp...

2016
Alejandro Maroto-Morales Olga García-Álvarez Manuel Ramón Felipe Martínez-Pastor M Rocío Fernández-Santos A Josefa Soler José Julián Garde

The spermatozoon is the most diverse cell type known and this diversity is considered to reflect differences in sperm function. How the diversity in sperm morphology arose during speciation and what role the different specializations play in sperm function, however, remain incompletely characterized. This work reviews the hypotheses proposed to explain sperm morphological evolution, with a focu...

Journal: :The Journal of veterinary medical science 2004
Tatsuya Hori Mitsue Ichikawa Eiichi Kawakami Toshihiko Tsutsui

Freeze-storage of epididymal sperm is an important technique for the preservation of gametes in animals, including those becoming extinct. We froze canine sperm recovered from the cauda epididymis and investigated the fertility. The qualities of sperm from the cauda epididymis before freezing were: mean sperm motility, 89.4 +/- 1.6 (SE) %; sperm viability, 89.1 +/- 1.1%; and these were signific...

2014
Cecilia S Blengini Naretto Sergio Cardozo Gabriela Laura C Giojalas Chiaraviglio Margarita

In polyandrous species, sperm morphometry and sperm velocity are under strong sexual selection. Although several hypotheses have been proposed to explain the role of sperm competition in sperm trait variation, this aspect is still poorly understood. It has been suggested that an increase in sperm competition pressure could reduce sperm size variation or produce a diversity of sperm to maximize ...

Journal: :iranian journal of applied animal science 2014
m.v. ghasemi a. ghorbani

the objective of this study was to evaluate the importance of environmental and genetic factors affecting semen quality; sperm volume (sv), sperm concentration (spco), total sperm (ts), fresh sperm motility (fsm), total fresh motile sperm (tfms), post thaw sperm motility (ptsm), total post thaw motile sperm (tptms), number of produced payout (npp), number of fresh motile sperm in each milt ejac...

Journal: :The Journal of Cell Biology 1982
B D Shur N G Hall

Past studies have suggested that mouse sperm surface galactosyltransferase may participate during fertilization by binding N-acetylglucosamine (GlcNAc) residues in the zona pellucida. In this paper, we examined further the role of sperm surface galactosyltransferase in mouse fertilization. Two reagents that specifically perturb sperm surface galactosyltransferase activity both inhibit sperm-zon...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Simone Immler Scott Pitnick Geoff A Parker Kate L Durrant Stefan Lüpold Sara Calhim Tim R Birkhead

Spermatozoa are amongst the most variable cells, and three factors are thought to account for this variation in design: fertilization mode, phylogeny, and postcopulatory sexual selection. In addition, it has long been assumed that a tradeoff exists between sperm size and number, and although postcopulatory sexual selection affects both traits, empirical evidence for a tradeoff has so far been e...

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