نتایج جستجو برای: sperm protamine

تعداد نتایج: 38734  

Hosseinifar H, Modarresi T Rasouli F, Sabbaghian M Sadighi Gilani MA

Background: Globozoospermia is an uncommon disorder of sperm morphology associated with severe male infertility. Patients who contain both normal and round-headed sperm are called partial globozoospermic. It is possible that round-headed sperm may have an abnormal chromatin structure and /or DNA strand breaks. Moreover, sperm DNA fragmentation and protamine deficiency is shown to be associated ...

2016
Gerly Sillaste Lauris Kaplinski Riho Meier Ülle Jaakma Elo Eriste Andres Salumets

DNA compaction with protamines in sperm is essential for successful fertilization. However, a portion of sperm chromatin remains less tightly packed with histones, which genomic location and function remain unclear. We extracted and sequenced histone-associated DNA from sperm of nine ejaculates from three bulls. We found that the fraction of retained histones varied between samples, but the var...

Journal: :Human reproduction 2009
M Kheirollahi-Kouhestani S Razavi M Tavalaee M R Deemeh M Mardani J Moshtaghian M H Nasr-Esfahani

BACKGROUND Reducing the percentage of sperm anomalies in insemination samples remains a goal to be achieved in the intra-cytoplasmic sperm insemination (ICSI) procedure. The aim of this study was to evaluate the efficiency of density gradient centrifugation (DGC) and Zeta methods to recover sperm with intact chromatin, and to evaluate whether the combined DGC/Zeta procedure improved ICSI outcom...

2011
Lena Lüke Alberto Vicens Francois Serra Juan Jose Luque-Larena Hernán Dopazo Eduardo R. S. Roldan Montserrat Gomendio

Sexual selection has been proposed as the driving force promoting the rapid evolutionary changes observed in some reproductive genes including protamines. We test this hypothesis in a group of rodents which show marked differences in the intensity of sexual selection. Levels of sperm competition were not associated with the evolutionary rates of protamine 1 but, contrary to expectations, were n...

2015
Judit Castillo Josep Maria Estanyol Josep Lluis Ballescà Rafael Oliva

The classical idea about the function of the mammalian sperm chromatin is that it serves to transmit a highly protected and transcriptionally inactive paternal genome, largely condensed by protamines, to the next generation. In addition, recent sperm chromatin genome-wide dissection studies indicate the presence of a differential distribution of the genes and repetitive sequences in the protami...

Journal: :cell journal 0

introduction: different methods have been used to evaluate the beneficial effect of varicocelectomy; these include semen parameters and pregnancy rate. due to high biological variability of semen parameters, sperm functional test has been considered an efficient end point in assessment of fertility. therefore, the aim of this study was to evaluate the effect of varicocelectomy on semen paramete...

Journal: :Human reproduction 2010
Craig Niederberger

BACKGROUND Protamine content is necessary for proper sperm chromatin condensation and subsequent male fertility. The exact effect of smoking on male fertility remains controversial. The objective of this study was to evaluate the effect of smoking on protamine content of sperm in smoker and non-smoker patients. METHODS Protamines 1 (P1) and 2 (P2) were quantified by gel electrophoresis in the...

Journal: :Nucleic acids research 1991
R Queralt R Oliva

Protamines are extremely variable and positively charged proteins which act by compacting the DNA in the sperm nucleus of many species (1). Their precise role and evolutionary pathways are not well understood at present probably because of the variable nature of these proteins and the corresponding sperm-associated structures together with the limited number of species with known protamine nucl...

Journal: :Genomics 2008
Nada Borghol Thierry Blachère Annick Lefèvre

The use of round spermatids that are fully active at the transcriptional level to create zygotes (i.e. round spermatid injection; ROSI) raises the question regarding the downregulation of all specific genes that are transcribed from the paternal genome at fertilization. In this study, we show that protamine 1 and 2 mRNAs, which are specific to the round spermatid stage, are repressed at the two...

Journal: :Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi 2009
Matthew Thomas Domenic Castignetti

BACKGROUND AND PURPOSE Based on their ability to chelate metals, hydroxamate molecules and siderophores have been successfully used as metalloenzyme inhibitors. As the anthrax toxin lethal factor (LF) is a zinc (Zn)-metallopeptidase, an investigation of the ability of some small non-siderophore hydroxamate compounds, 5 hydroxamate-containing siderophores, and 1 catecholate siderophore was under...

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