نتایج جستجو برای: sperm head

تعداد نتایج: 203185  

2013
Manuel Ramón M. Dolores Pérez-Guzmán Pilar Jiménez-Rabadán Milagros C. Esteso Olga García-Álvarez Alejandro Maroto-Morales Luis Anel-López Ana J. Soler M. Rocío Fernández-Santos J. Julián Garde

BACKGROUND Sperm cryopreservation has become an indispensable tool in biology. Initially, studies were aimed towards the development of efficient freezing protocols in different species that would allow for an efficient storage of semen samples for long periods of time, ensuring its viability. Nowadays, it is widely known that an important individual component exists in the cryoresistance of se...

Journal: :The Journal of reproduction and development 2006
Yasuhiro Kawai Tomoko Hata Osamu Suzuki Junichiro Matsuda

In vitro fertilization (IVF) is widely used in reproduction research, but the sperm of some inbred strains of mice yield low fertilization rates in IVF. To determine the cause of this problem, we examined the effect of epididymal sperm morphology, in particular, tail bending and the presence and type of cytoplasmic droplet (CD), on fertilizability in vitro. Sperm suspensions were obtained from ...

Azim Hedayatpour, Fardin Amidi, Farid Abolhassani, Hoshang Rafigdust, Kunihiro Okamura, Marefat Ghaffari, Sou-ichi Nakamura, Yukihiro Terada,

In human fertilization, the sperm centrosome nucleates a radial array of microtubules called the sperm aster. The sperm aster is responsible for apposition of male and female pronuclei, and later gives rise to the first meiotic spindle. The objective of this study was to determine microtubule assembly and chromatin configuration in rabbit oocytes following intracytoplasmic injection with human ...

Journal: :international journal of reproductive biomedicine 0
sundararajan venkatesh m.pharm gurdeep singh narmada prasad gupta rajeev kumar munusamy deecaraman rima dada

background: excess reactive oxygen species (ros) in the semen is believed to affect fertility in men. morphologically abnormal sperms and their relation to seminal oxidative stress in infertile and subfertile men are not clear. objective: to correlate various sperm morphological defects with seminal oxidative stress in infertile and subfertile men. materials and methods: the study included 25 p...

Fallahkarkan M Jalalsafari Mohamadghasemi Ranjbar S,

Background: Cigarette smoking is associated with impairment of testicular function. Nicotine is a major component of cigarette smoke.In the present study we aimed to study the effect of administration of nicotine-melatonin on sperm parameters in adult mouse. Materials and Methods: Male NMRI mice were divided into 4 groups: 1) control(normal saline) group 2) nicotine treated group 3) melatonin t...

2009
Charles C. Love

Introduction: There are many tests that describe semen quality in the stallion which include sperm motility, morphology, and longevity of motility and determination of total sperm numbers. In addition, recently, the flow cytometer (FC) has been used to evaluate various sperm compartment following staining with specific fluorescent probes that bind to different compartments of the sperm. Our lab...

2015
Yan Liu Kathleen DeBoer David M. de Kretser Liza O’Donnell Anne E. O’Connor D. Jo Merriner Hidenobu Okuda Belinda Whittle David A. Jans Athina Efthymiadis Robert I. McLachlan Christopher J. Ormandy Chris C. Goodnow Duangporn Jamsai Moira K. O’Bryan

Male infertility affects at least 5% of reproductive age males. The most common pathology is a complex presentation of decreased sperm output and abnormal sperm shape and motility referred to as oligoasthenoteratospermia (OAT). For the majority of OAT men a precise diagnosis cannot be provided. Here we demonstrate that leucine-rich repeats and guanylate kinase-domain containing isoform 1 (LRGUK...

Journal: :The Journal of Cell Biology 1991
C J Brokaw

Direct measurements of microtubule sliding in the flagella of actively swimming, demembranated, spermatozoa have been made using submicron diameter gold beads as markers on the exposed outer doublet microtubules. With spermatozoa of the tunicate, Ciona, these measurements confirm values of sliding calculated indirectly by measuring angles relative to the axis of the sperm head. Both methods of ...

2016
Weng Chun Tan Nor Ashidi Mat Isa

In human sperm motility analysis, sperm segmentation plays an important role to determine the location of multiple sperms. To ensure an improved segmentation result, the Laplacian of Gaussian filter is implemented as a kernel in a pre-processing step before applying the image segmentation process to automatically segment and detect human spermatozoa. This study proposes an intersecting cortical...

Journal: :Evolution; international journal of organic evolution 2011
Outi Ala-Honkola Mollie K Manier Stefan Lüpold Scott Pitnick

Selection to avoid inbreeding is predicted to vary across species due to differences in population structure and reproductive biology. Over the past decade, there have been numerous investigations of postcopulatory inbreeding avoidance, a phenomenon that first requires discrimination of mate (or sperm) relatedness and then requires mechanisms of male ejaculate tailoring and/or cryptic female ch...

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