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
References in periodicals archive ?
Therefore, natural and synthetic antioxidants are frequently added in semen extender to inhibit peroxidation of sperm cell phospholipids, particularly of the polyunsaturated fatty acids.
Treatment of spermatozoa culture media: The culture medium without sperm cells was centrifuged in 1.
If more than one sperm cell penetrates the zona and fertilizes an egg, the result will be an embryo with an abnormal number of chromosomes (two sperm fertilizing an egg results in an embryo with 69 chromosomes instead of 46).
For example, in humans the first fraction contains the highest concentration of sperm cells and primarily fluid secreted by the prostate gland.
The wide lumen is filled with different kinds of secretions forming distinct globules and mature sperm cells (Fig.
In the control experiments, abalone sperm cells were incubated with FAM-labeled 10 met oligonucleotide (10 [micro]M) for 2 h, then rinsed and fixed.
Sperm cells are the most delicate in the male body; exposure to low levels of toxic chemicals, which might not harm hardier cells, can kill them in large numbers.
ABSTRACT : The objective of this study was to compare random regression model and multiple trait animal model estimates of the (co) variance of total sperm cells over the active lifetime of AI boars.
The sperm moves toward the egg by chemotaxis, which is movement by the sperm cell in reaction to chemical signals, sent out by the egg cell.
Sperm morphology as well as immature sperm cell evaluation are important in spermatogenesis evaluation.
This particular sperm cell divides and contributes genes to the next generation.