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acrosome

 
Dictionary: ac·ro·some   (ăk'rə-sōm') pronunciation
 
n.

A caplike structure at the anterior end of a spermatozoon that produces enzymes aiding in egg penetration.

[ACRO– + –SOME3.]

acrosomal ac'ro·so'mal (-sō'məl) adj.
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Veterinary Dictionary: acrosome
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The caplike, membrane-bounded structure that covers the anterior portion of the head of the mammalian spermatozoon; it is bounded by an inner and an outer membrane and contains enzymes involved in penetration of the ovum.

  • a. reaction — fusion of the outer acrosomal membrane with the sperm plasma membrane, and the breakdown of the fused complex, after the attachment of the spermatozoon to the zona pellucida. It is induced by substances from the egg investments and releases enzymes involved in penetration of the ovum.
 
Wikipedia: Acrosome
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In spermatozoa (also known as sperm/sperm cell) of many animals, the Acrosome is an organelle that develops over the anterior half of the sperm's head. It is a cap-like structure derived from the Golgi apparatus. Acrosome formation is completed during testicular maturation. In Eutherian mammals the acrosome contains digestive enzymes (including hyaluronidase and acrosin). [1] These enzymes break down the outer membrane of the ovum called the zona pellucida, allowing the haploid nuclei in the sperm to join with the haploid nucleus found in the ova.

This shedding of the acrosome or Acrosome reaction can be stimulated in vitro by substances a sperm cell may encounter naturally such as progesterone or follicular fluid, as well as the more commonly used calcium ionophore A23187. This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry [2] or fluoresence microscopy. This is usually done after staining with a fluoresceinated lectin such as FITC-PNA, FITC-PSA, FITC-ConA, or fluoresceinated antibody such as FITC-CD46.[3]

Human spermatozoön

See also

References

  1. ^ "acrosome definition - Dictionary - MSN Encarta". http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861695331. Retrieved on 2007-08-15. 
  2. ^ Miyazaki et al. Archives of Andrology 25:243-251 (1990)
  3. ^ Carver-Ward et al. Journal of Assisted Reproduction and Genetics, Vol. 14, no. 2, 1997

 
 

 

Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Acrosome" Read more