نتایج جستجو برای: sperm tail
تعداد نتایج: 87689 فیلتر نتایج به سال:
Globozoospermia is a rare disorder characterized by the presence of sperm with round head, lacking acrosome. Coiling tail around the nucleus has been reported since early human studies, but no specific significance has conferred it. By contrast, studies on animal models suggest that coiling tail around the nucleus could represent a crucial step of defective spermatogenesis, resulting in round-h...
previous studies have indicated that fish oil intake wi1l improve semen quality in some mammals and birds. the aim of this study was to investigate the effect of dietary fish oil on reproductive performance in ram. eight zandi rams were divided into two groups and fed either a control diet or a supplemented diet with fish oil. both of the diets were isocaloric and isonitrogenous and formulated ...
The brooding bivalves, Nutricola tantilla and N. confusa overlap in their geographic distributions, habitats, and modes and timing of reproduction. Based on previous studies we infer that males of both species release spermatozoa into the water column; while females retain developing embryos in a brood chamber. Females release fully formed juveniles and there is no pelagic larval stage. We hypo...
The motion of the sea urchin sperm flagellum was analyzed from high-speed cinemicrographs. At all locations on the flagellum the transversal motion and the curvature were found to vary sinusoidally in time. The curvatures of the flagella increase strongly near the proximal junction. Two sperm are described in transient from rest to normal motion. The full wave motion developed in both sperm wit...
We aim to visualize the external physical damages and distinct external phenotypic effects between mechanical and laser-assisted immobilized human spermatozoa using scanning electronic microscopy (SEM). Human spermatozoa were immobilized mechanically or with laser assistance for SEM examination and the membrane integrities were checked on both types of immobilized spermatozoa. We found evidence...
In this study, a gene coding a novel human sperm tail protein named NYD-SP28 was cloned and characterized using a complementary DNA (cDNA) microarray. Its expression was 3.5 times higher in human testis than in fetal testis, and very high in human spermatozoa. The full length of NYD-SP28 cDNA was 1798 bp and encoded a 484-amino-acid protein. Motif analysis revealed that the protein contained a ...
It has been reported that Shorr staining provides additional morphological information on the motility of spermatozoa in semen, by distinguishing between red and blue flagella. With our routine methods (involving mounting slides) we were unable to confirm these observations. The presence of both red- and blue-coloured sperm tails in Shorr-stained semen smears was apparent, however, if slides we...
Males and hermaphrodites are the two naturally found sexual forms in the nematode C. elegans. The amoeboid sperm are produced by both males and hermaphrodites. In the earlier phase of gametogenesis, the germ cells of hermaphrodites differentiate into limited number of sperm--around 300--and are stored in a small 'bag' called the spermatheca. Later on, hermaphrodites continually produce oocytes....
BACKGROUND Sperm have but one purpose, to fertilize an egg. In various species including Drosophila melanogaster female sperm storage is a necessary step in the reproductive process. Amo is a homolog of the human transient receptor potential channel TRPP2 (also known as PKD2), which is mutated in autosomal dominant polycystic kidney disease. In flies Amo is required for sperm storage. Drosophil...
sperms are highly specialized cells for delivering dna from male to the ovum. incredibly, wide degree of diversity in sperm morphology in their basic structures i.e. head, middle piece and tail is found across species. differences in terms of overall size of the sperm, shape and number of sperm produced are also incredible. one of the key for this variations or diversity in sperm may be associa...
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