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Diagram of a human spermatozoa showing the acrosome

The acrosome is an organelle that develops over the anterior (front) half of the head in the spermatozoa (sperm cells) of humans, and many other animals. It is a cap-like structure derived from the Golgi apparatus. In placental mammals, the acrosome contains degradative enzymes (including hyaluronidase and acrosin). [1] These enzymes break down the outer membrane of the ovum, [2] called the zona pellucida, allowing the haploid nucleus in the sperm cell to join with the haploid nucleus in the ovum. This shedding of the acrosome, or acrosome reaction, can be stimulated in vitro by substances a sperm cell may encounter naturally such as progesterone [3] or follicular fluid, as well as the more commonly used calcium ionophore A23187. [4] This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry [5] or fluorescence 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. [6]

In the case of globozoospermia (sperm with round heads), the Golgi apparatus is not transformed into the acrosome, causing male infertility. [7]

See also

References

  1. ^ "acrosome definition - Dictionary - MSN Encarta". Archived from the original on 2009-02-14. Retrieved 2007-08-15.
  2. ^ Larson, Jennine L.; Miller, David J. (1999). "Simple histochemical stain for acrosomes on sperm from several species". Molecular Reproduction and Development. 52 (4): 445–449. doi: 10.1002/(SICI)1098-2795(199904)52:4<445::AID-MRD14>3.0.CO;2-6. ISSN  1098-2795. PMID  10092125. S2CID  24542696.
  3. ^ Lishko, Polina V.; Botchkina, Inna L.; Kirichok, Yuriy (March 2011). "Progesterone activates the principal Ca 2+ channel of human sperm". Nature. 471 (7338): 387–391. Bibcode: 2011Natur.471..387L. doi: 10.1038/nature09767. ISSN  1476-4687. PMID  21412339. S2CID  4340309.
  4. ^ Jamil, K.; White, I. G. (December 1981). "Induction of acrosomal reaction in sperm with ionophore A23187 and calcium". Archives of Andrology. 7 (4): 283–292. doi: 10.3109/01485018108999319. ISSN  0148-5016. PMID  6797354.
  5. ^ Miyazaki R, Fukuda M, Takeuchi H, Itoh S, Takada M (1990). "Flow cytometry to evaluate acrosome-reacted sperm". Arch. Androl. 25 (3): 243–51. doi: 10.3109/01485019008987613. PMID  2285347.
  6. ^ Carver-Ward JA, Moran-Verbeek IM, Hollanders JM (February 1997). "Comparative flow cytometric analysis of the human sperm acrosome reaction using CD46 antibody and lectins". J. Assist. Reprod. Genet. 14 (2): 111–9. doi: 10.1007/bf02765780. PMC  3454831. PMID  9048242.
  7. ^ Hermann Behre; Eberhard Nieschlag (2000). Andrology : Male Reproductive Health and Dysfunction. Berlin: Springer. p. 155. ISBN  3-540-67224-9.