نتایج جستجو برای: sperm penetration distance

تعداد نتایج: 308753  

2012
Boris Baibakov Nathan A. Boggs Belinda Yauger Galina Baibakov Jurrien Dean

Fertilization requires taxon-specific gamete recognition, and human sperm do not bind to zonae pellucidae (ZP1-3) surrounding mouse eggs. Using transgenesis to replace endogenous mouse proteins with human homologues, gain-of-function sperm-binding assays were established to evaluate human gamete recognition. Human sperm bound only to zonae pellucidae containing human ZP2, either alone or coexpr...

Journal: :Animal reproduction science 2011
C Matás L Vieira F A García-Vázquez K Avilés-López R López-Úbeda J A Carvajal J Gadea

In this study, different combinations of 2-step, discontinuous gradient centrifugation were used, consisting of three different combinations of isotonic Percoll (45/60, 60/75 and 45/90%) that allowed us to select different sperm subpopulations from fertile and normozoospermic boars. Our objective in this study is to evaluate the effects of centrifugation through three different discontinuous Pe...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2002
Hitoshi Sawada Naoyuki Sakai Yukichi Abe Etsuko Tanaka Youko Takahashi Junko Fujino Eri Kodama Satoshi Takizawa Hideyoshi Yokosawa

The ubiquitin-proteasome system is essential for intracellular protein degradation, but an extracellular role of this system has not been known until now. We have previously reported that the proteasome is secreted into the surrounding seawater from sperm of the ascidian (Urochordata) Halocynthia roretzi on sperm activation, and that the sperm proteasome plays a key role in fertilization. Here,...

2014
A. R. Elkhawagah V. Longobardi B. Gasparrini G. A. Sosa G. Bifulco

This study aimed to determine the most reliable method to evaluate capacitation of buffalo frozen/thawed sperm. Frozen/thawed sperm were incubated in TALP medium in absence of capacitating agents (control) and in presence of 10 μg/ml heparin for 2 and 4 hrs. Capacitation was assessed by Trypan blue/Giemsa after lysophosphatidylecholine (LPC) exposure, chlortetracycline (CTC) fluorescence assay ...

Journal: :Australian Journal of Biological Sciences 1951

Journal: :Theriogenology 2009
P Coy J Gadea D Rath R H F Hunter

The penetration ability of boar (Sus scrofa domestica) spermatozoa exposed to viscous preparations under in vivo and in vitro fertilization conditions has been examined. Experiments involving induced ovulation in prepubertal animals and surgical insemination directly into the oviduct isthmus revealed an advantage of colloidal preparations. Based on within-animal comparisons, the incidence of pe...

Journal: :Frontiers in bioscience : a journal and virtual library 2000
E Baldi M Luconi L Bonaccorsi M Muratori G Forti

Two processes, namely capacitation and acrosome reaction, are of fundamental importance in the fertilization of oocyte by spermatozoon. Physiologically occurring in the female genital tract, capacitation is a complex process, which renders the sperm cell capable for specific interaction with the oocyte. During capacitation, modification of membrane characteristics, enzyme activity and motility ...

Journal: :Developmental biology 2003
Naoyuki Sakai Hitoshi Sawada Hideyoshi Yokosawa

The ubiquitin-proteasome system is essential for intracellular protein degradation, but there are few studies of this system in the extracellular milieu. Recently, we reported that a 70-kDa sperm receptor, HrVC70, on the vitelline coat is ubiquitinated and then degraded by the sperm proteasome during fertilization of the ascidian, Halocynthia roretzi. Here, we investigated the mechanism of extr...

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