Sperm cell


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Sperm cell

The male gamete. The typical sperm of most animals has a head containing the nucleus and acrosome, a middle piece with the mitochondria, and a tail with the 9 + 2 microtubule pattern (see illustration). Sperm, as well as the acrosome shape, varies with the species. The nucleus consists of condensed chromatin (deoxyribonucleic acid, DNA) and histone proteins. The acrosome, which is derived from the Golgi complex, contains hydrolytic enzymes, that is, hyaluronidase capable of lysing the egg coats at fertilization. Actin molecules which aid in the interaction between sperm and egg are found in the area between the acrosome and nucleus. The mitochondria in the middle piece apparently provide the energy necessary for the motility created by the tail. The tail has a central core, or axial filament, made up of nine double tubules and two central tubules. See Cilia and flagella

Many groups, including nematodes, myriapods, and crustaceans, have atypical sperm which lack a flagellum and are presumably nonmotile. The sperm of Ascaris is round and moves by ameboid means. The crustacean sperm have a large acrosome of several components. In the anomurans a middle with mitochondria and arms filled with microtubules precedes the nucleus. In the true crabs the nucleus forms arms which possess microtubules and also surrounds the many component acrosomes. The nucleus of crustacean sperm does not condense with maturation as it does in typical sperm mentioned above. See Spermatogenesis

Diagram of a human spermatozoon, based on electron micrographsenlarge picture
Diagram of a human spermatozoon, based on electron micrographs
McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
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For data processing, one hundred sperm cells were counted and the images were evaluated using the Image Pro Plus software, version 6.2.1.
In a concluding section, we will present our expectations regarding the future importance of the proposed combined photonic technique as an efficient method for healthy and fertile living sperm cell selection, without injuring the sample, improving assisted reproduction technique outcomes and increasing the pregnancy rate.
Complete or incomplete stained spermatozoa (head) were counted as dead and sperm cells having no stain penetration were considered as live (Ijaz et al., 2009).
An intermittent but long-lasting antigenic stimulus supported by appropriate cytokines like TGFAY1 is required to produce partner-specific mucosal immune tolerance.14 Antigenic factor lies on the spermatozoa cell but not on sperm cells in seminal fluid prepared for insemination.15 Wang et al16 evaluated
The effect of trapping on the sperm motility is quantified hereafter as the trapping efficiency of our optical tweezers set-up for sperm cells. This was calculated using the following formula [30]:
Extraction of total protein from sperm cells and slide preparation: To extract proteins from sperm cells, 5x [10.sup.6] sperm/ml of sperm cells were centrifuged for 5 min at 5,000 rpm.
Conceptually, when sperm cells enter the aperture, the voltage trace rises to a certain level with undulation owing to the sperm's vibration, and the signal reduces to the original level once the sperm leaves the aperture.
Once the nucleus of the sperm cell enters the oocyte, it decondenses.
The sperm cells show no tendency to form well ordered piles or globules either in the lumina of the testes or in the vasa deferentia.
Then the FAM-labeled oligonucleotides and the PEI/oligonucleotides mixture was added to the sperm cells, mixed, vortexed, spun down, and incubated at room temperature for 60 min.
5 Kyodo Laboratory experiments on mice show that exposure to particulate matter from diesel engine exhaust diminishes sperm cell production, researchers from the Science University of Tokyo's pharmacology department said Monday.
Each egg and sperm cell, therefore, ended with only half the usual number of chromosomes.