The acrosome is an organelle that develops over the anterior half of the head in the Spermatozoon spermatozoa sperm cell of many animals. It is a cap like structure derived from the Golgi apparatus . Acrosome formation is completed during testicular maturation. In Eutheria n mammals the acrosome contains digestive enzyme s including hyaluronidase and acrosin . ref cite web url http encarta.msn.com encnet features dictionary DictionaryResults.aspx?refid 1861695331 title acrosome definition Dictionary MSN Encarta accessdate 2007 08 15 format work archiveurl http www.webcitation.org 5kwDPQanq archivedate 2009 10 31 deadurl yes ref These enzymes break down the outer membrane of the ovum , called the zona pellucida , allowing the haploid Cell nucleus 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 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 ref Miyazaki et al. Archives of Andrology 25 243 251 1990 ref or Fluorescence microscope 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. ref Carver Ward et al. Journal of Assisted Reproduction and Genetics, Vol. 14, no. 2, 1997 ref Image Simplified spermatozoon diagram.svg thumb center 550px Human spermatozo n In the case of globozoospermia sperm with round heads , the Golgi apparatus is not transformed into the acrosome , causing male infertility . ref Page 155 in cite book author Hermann ... Akrosoom bs Akrozom bg ca Acrosoma cs Akrozom de Akrosom el es Acrosoma fr Acrosome ko lt Akrosoma ja pl Akrosom ro Acrozom ru sr sh Akrozom sv Akrosom tl Acrosome ... more details
File Acrosome reaction diagram en.svg thumb 390px right Acrosome reaction on a Sea Urchin cell During ... a process known as the acrosome reaction which is the reaction that occurs in the acrosome of the sperm as it approaches the egg. The acrosome is a cap like structure over the anterior half of the sperm ... the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane of the sperm, exposing the contents of the acrosome. The contents include surface antigens and numerous ... of the acrosome reaction. In several species the trigger for the acrosome reaction has ... the acrosome reaction releases hyaluronidase and acrosin their role in fertilization is not yet clear ... so that it can fuse with the egg plasma membrane. A sperm penetration assay includes an acrosome reaction ... that are unable to properly go through the acrosome reaction will not be able to fertilize an egg ... and provides limited information on a man s fertility. ref Your path to fertility Acrosome ... mouse Apodemus sylvaticus , premature acrosome reactions have been found to cause increased motility ... oocyte. A few events precede the actual acrosome reaction . The sperm cell acquires a hyperactive ..., by releasing hyaluronidase from the acrosome to digest cumulus cells surrounding the oocyte and exposing ... it as it grows. After reaching the Zona Pellucida the actual acrosome reaction begins. Acrosin digests ... evidence that this binding is what triggers the acrosome to release the enzymes that allow ... cells will undergo a spontaneous acrosome reaction without the presence of the ovum. Those cells ... shed their acrosome during the process of apoptosis necrosis. In in vitro fertilization When using intracytoplasmic ... that have undergone acrosome reaction 40 vs. those injected with nonreacted spermatozoa ... issue pages year 2008 month December pmid 19064263 doi 10.1016 j.fertnstert.2008.10.024 url ref The acrosome ... for assessing the shedding of the acrosome or acrosome reaction of a sperm sample. Flow cytometry and fluorescence ... more details
Multiple issues orphan April 2009 expert April 2009 Spermatozoon Spermatozoa develop in the seminiferous tubules of the testes. During their development the Spermatogonium spermatogonia proceed through meiosis to become spermatozoa. Many changes occur during this process the DNA in nuclei becomes condensed the acrosome develops as a structure close to the nucleus. The acrosome is derived from the Golgi apparatus and contains hydrolytic enzymes important for fusion of the spermatozoon with an Ovum egg cell . During spermiogenesis the nucleus condenses and changes shape. Abnormal shape change is a feature of sperm in Infertility male infertility . The acroplaxome is the name that has been given to describe a structure that is found between the acrosomal membrane and the Nuclear envelope nuclear membrane . ref name Kiersz03 cite journal author Kierszenbaum AL, Rivkin E, Tres LL title Acroplaxome, an F actin keratin containing plate, anchors the acrosome to the nucleus during shaping of the spermatid head journal Mol. Biol. Cell volume 14 issue 11 pages 4628 40 year 2003 month November pmid 14551252 pmc 266778 doi 10.1091 mbc.E03 04 0226 url http www.molbiolcell.org cgi content full 14 11 4628 ref The acroplaxome contains structural proteins including keratin 5, Actin F actin ref name Kiersz03 and profilin IV. ref cite journal author Obermann H, Raabe I, Balvers M, Brunswig B, Schulze W, Kirchhoff C title Novel testis expressed profilin IV associated with acrosome biogenesis and spermatid elongation journal Mol. Hum. Reprod. volume 11 issue 1 pages 53 64 year 2005 month January pmid 15591451 doi 10.1093 molehr gah132 url http molehr.oxfordjournals.org cgi content full 11 1 53 ref References cite journal author Kierszenbaum AL, Tres LL title The acrosome acroplaxome manchette complex and the shaping of the spermatid head journal Arch. Histol. Cytol. volume 67 issue 4 pages 271 84 year 2004 month November pmid 15700535 reflist Category Cell biology ... more details
Acron may refer to TOCright Business Acron Group Russian and global mineral fertiliser company People Acron son of Xenon, an ancient Greek physician Acron or Acro, a king of the Caeninenses, whom Romulus slew in battle. See Epithets of Jupiter Helenius Acron , the 2nd century commentator Places Acron, Florida , a ghost town in the United States Science Prostomium or acron , the first body segment of Annelid worms Acrosome or acron , the anterior part of a spermatozoon See also Akron disambiguation disambig SmithDGRBM ca cron desambiguaci ru ... more details
Refimprove date August 2009 File Acrosome reaction diagram en.svg thumb 400px The acrosome reaction for a sea urchin, a similar process. Note that the picture shows several stages of one and the same spermatozoon only one penetrates the ovum Human fertilisation fertilization is the union of a human ovum egg and spermatozoon sperm , usually occurring in the Ampulla of uterine tube ampulla of the uterine tube . The result of this union is the production of a new individual of the human species homo sapiens , complete with a unique set of the 23 pairs of chromosomes that genetically specify a human organism, the sperm and the egg each providing 23, for a total of 46 chromosomes. It is also the initiation of prenatal development . Scientists discovered the dynamics of human fertilisation in the nineteenth century. ref Garrison, Fielding. http books.google.com books?id JvoIAAAAIAAJ&pg PA567&dq fetilisation was discovered hertwig&num 100&ei nQiGSYDYGouiyATyvuSnDQ PPA567,M1 An Introduction to the History of Medicine , pages 566 567 Saunders 1921 . ref The process of fertilization involves a sperm fusing with an ovum usually following ejaculation during sexual intercourse . It is possible, but less probable, for fertilization to occur without sexual intercourse, artificial insemination , or In vitro fertilisation . ref http www.goaskalice.columbia.edu 0116.html ref ref http www.americanpregnancy.org preventingpregnancy pregnancyfaqmyths.html ref ref Lawyers Guide to Forensic Medicine ISBN 978 1859411599 By Bernard Knight Page 188 Pregnancy is well known to occur from such external ejaculation ... ref Upon encountering the ovum, the acrosome of the sperm produces enzymes which allow ... accessdate 2010 10 16 ref Acrosome reaction The acrosome reaction must occur to mobilise enzymes within ... to a ZP2 glycoprotein in the zona pellucida. This binding triggers the acrosome to burst, releasing enzymes that help the sperm get through the zona pellucida. Some sperm cells consume their acrosome ... more details
Infobox Anatomy Name Spermatid Latin GraySubject 258 GrayPage 1243 Image Germinal epithelium testicle.svg Caption Germinal epithelium of the testicle . BR 1 basal lamina BR 2 spermatogonia BR 3 spermatocyte 1st order BR 4 spermatocyte 2nd order BR 5 spermatid BR 6 mature spermatid BR 7 Sertoli cell BR 8 tight junction blood testis barrier Image2 Gray1150.png Caption2 Transverse section of a tubule of the testis of a rat . X 250. System MeshName Spermatids MeshNumber A05.360.490.890.860 The spermatid is the haploid male gametid that results from division of secondary spermatocyte s. As a result of meiosis , each spermatid contains only half of the genetic material present in the original primary spermatocyte. Spermatids are connected together by cytoplasmic material and have superfluous cytoplasmic material around their nuclei. When formed, early round spermatids must undergo further maturational events in order to develop into spermatozoa , a process termed spermiogenesis also termed spermeteliosis . The spermatids begin to grow a living thread, develop a thickened mid piece where the mitochondria become localised, and form an acrosome . Spermatid DNA also undergoes packaging, becoming highly condensed. The DNA is packaged firstly with specific nuclear basic proteins, which are subsequently replaced with protamines during spermatid elongation. The resultant tightly packed chromatin is transcriptionally inactive. Additional images gallery Image Gray7.png Scheme showing analogies in the process of maturation of the ovum and the development of the spermatids young spermatozoa . gallery External links BUHistology 17804loa Male Reproductive System testis, early spermatids BUHistology 17805loa Male Reproductive System testis, late spermatids http www.cvm.okstate.edu instruction mm curr histology MR HiMRp3.htm Histology at okstate.edu Male reproductive system Category Reproductive system Category Germ cells Category Andrology ar de Spermatide fr Spermatide io S ... more details
enzyme Name acrosin EC number 3.4.21.10 CAS number 9068 57 9 IUBMB EC number 3 4 21 10 GO code 0004284 image Acrosin 1FIW.png width caption PBB geneid 49 Acrosin is a digestive enzyme that acts as a protease . In humans, acrosin is encoded by the ACR gene . ref name pmid2298447 cite journal author Adham IM, Klemm U, Maier WM, Engel W title Molecular cloning of human preproacrosin cDNA journal Hum. Genet. volume 84 issue 2 pages 125 8 year 1990 month January pmid 2298447 doi url issn ref ref name pmid12398221 cite journal author Honda A, Siruntawineti J, Baba T title Role of acrosomal matrix proteases in sperm zona pellucida interactions journal Hum. Reprod. Update volume 8 issue 5 pages 405 12 year 2002 pmid 12398221 doi 10.1093 humupd 8.5.405 url issn ref Acrosin is released from the acrosome of spermatozoa as a consequence of the acrosome reaction . It aids in the penetration of the Zona Pellucida . Function Acrosin is the major proteinase present in the acrosome of mature spermatozoa. It is a typical serine proteinase with trypsin like specificity. It is stored in the acrosome in its precursor form, proacrosin. The active enzyme functions in the lysis of the zona pellucida, thus facilitating penetration of the sperm through the innermost glycoprotein layers of the ovum. The mRNA for proacrosin is synthesized only in the postmeiotic stages of spermatogenesis. In humans proacrosin first appears in the haploid spermatids. ref name entrez cite web title Entrez Gene acrosin url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 49 accessdate ref References Reflist Further reading refbegin 2 cite journal author Elce JS, McIntyre EJ title Purification of bovine and human acrosin. journal Can. J. Biochem. volume 60 issue 1 pages 8 14 year 1982 pmid 6802470 doi 10.1139 o82 002 cite journal author Zheng X, Geiger M, Ecke S, et al. title Inhibition of acrosin by protein C inhibitor and localization of protein C inhibitor to spermatozoa. journal A ... more details
activation main Acrosome reaction Image Acrosome reaction diagram en.svg thumb 440px left Acrosome ... in sperm activation is the acrosome reaction . This involves releasing the contents of the acrosome ... is what triggers the acrosome to release the enzymes that allow the sperm to fuse with the egg ... more details
is released by the acrosome of the Spermatozoon sperm cell after it has reached the oocyte .... Once this occurs, the sperm is capable of binding with the zona pellucida, and the acrosome reaction ... more details
Orphan date February 2009 PBB geneid 124912 Sperm acrosome membrane associated protein 3 is a protein that in humans is encoded by the SPACA3 gene . ref name pmid12606493 cite journal author Mandal A, Klotz KL, Shetty J, Jayes FL, Wolkowicz MJ, Bolling LC, Coonrod SA, Black MB, Diekman AB, Haystead TA, Flickinger CJ, Herr JC title SLLP1, a unique, intra acrosomal, non bacteriolytic, c lysozyme like protein of human spermatozoa journal Biol Reprod volume 68 issue 5 pages 1525 37 year 2003 month Apr pmid 12606493 pmc doi 10.1095 biolreprod.102.010108 ref ref name entrez cite web title Entrez Gene SPACA3 sperm acrosome associated 3 url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 124912 accessdate ref The PBB Summary template is automatically maintained by Protein Box Bot. See Template PBB Controls to Stop updates. PBB Summary section title summary text References reflist Further reading refbegin 2 PBB Further reading citations cite journal author Niyonsaba F, Ogawa H title Protective roles of the skin against infection implication of naturally occurring human antimicrobial agents beta defensins, cathelicidin LL 37 and lysozyme. journal J. Dermatol. Sci. volume 40 issue 3 pages 157 68 year 2006 pmid 16150577 doi 10.1016 j.jdermsci.2005.07.009 cite journal author Cramer EM, Breton Gorius J title Ultrastructural localization of lysozyme in human neutrophils by immunogold. journal J. Leukoc. Biol. volume 41 issue 3 pages 242 7 year 1987 pmid 3470418 doi cite journal author Welsh IR, Spitznagel JK title Distribution of lysosomal enzymes, cationic proteins, and bactericidal substances in subcellular fractions of human polymorphonuclear leukocytes. journal Infect. Immun. volume 4 issue 2 pages 97 102 year 1973 pmid 5154881 doi pmc 416271 cite journal author Ibrahim HR, Matsuzaki T, Aoki T title Genetic evidence that antibacterial activity of lysozyme is independent of its catalytic function. journal FEBS Lett. volume 506 issue 1 pages 27 32 year ... more details
Cleanup date February 2009 spermia Teratospermia or teratozoospermia is a condition characterized by the presence of sperm with abnormal morphology that affects fertility in males. Causes The causes of teratospermia are unknown in most cases. However, Hodgkin s disease, coeliac disease, and Crohn s disease may contribute in some instances. ref http www.gfmer.ch Endo Lectures 09 dupan1.htm ref In case of globozoospermia sperm with round heads , the Golgi apparatus is not transformed into the acrosome that is needed for fertilization . ref Page 155 in cite book author Hermann Behre Eberhard Nieschlag title Andrology Male Reproductive Health and Dysfunction publisher Springer location Berlin year 2000 pages isbn 3 540 67224 9 oclc doi accessdate ref Symptoms and treatment The presence of abnormally shaped sperm can negatively affect fertility by reducing sperm motility and or preventing sperm from adhering to the ovum . Achieving a pregnancy may be difficult. ref name gfmer.ch http www.gfmer.ch Endo Lectures 09 dupan.htm ref In testing for teratospermia, sperm are collected and analyzed under a microscope to detect abnormalities. These abnormalities may include heads that are large, small, tapered, or pyriform or tails that are abnormally shaped. ref http www.endotext.org male male7 male7 2.htm ref Antiestrogens have been shown to be effective in the treatment of teratospermia. ref name gfmer.ch Teratozoospermia including the globozoospermia ref cite journal author Egashira A, Murakami M, Haigo K, Horiuchi T, Kuramoto T title A successful pregnancy and live birth after intracytoplasmic sperm injection with globozoospermic sperm and electrical oocyte activation journal Fertil. Steril. volume issue pages year 2009 month September pmid 19800059 doi 10.1016 j.fertnstert.2009.08.013 url ref type , may be treated by intracytoplasmic sperm injection ICSI , injecting sperm directly into the egg. ref name french cite journal author French DB, Sabanegh ES, Goldfarb J, Desai N ti ... more details
on acrosome reaction and zona pellucida binding of human spermatozoa journal Biol. Reprod. volume ... Y, Li K, Xu W, et al. title Acrosome reaction induced by recombinant human zona pellucida 3 peptides ... more details
Immunocontraception is a birth control method that uses the body s immune response to prevent pregnancy . In humans Experiments are undergoing to test the effectiveness of an immunocontraceptive vaccine that inhibits the fusing of spermatozoa to the zona pellucida . This vaccine is currently being tested in animals and hopefully will be an effective contraceptive for humans. Normally, spermatozoa fuse with the zona pellucida surrounding the mature oocyte the resulting acrosome reaction breaks down the egg s tough coating so that the sperm can fertilize the oovum. The mechanism of the vaccine is injection with cloned ZP cDNA, therefore this vaccine is a DNA based vaccine. This results in the production of antibodies against the ZP, which stop the sperm from binding to the zona pellucida and ultimately from fertilizing the oovum. ref name Markert Markert U. Immunology of gametes and embryo implantation. Switzerland Karger 2005. ref Another vaccine in investigation is one against HCG. This immunization would produce antibodies against hCG and TT. Antibodies against hCG would prevent the maintenance of the uterus for a viable pregnancy therefore preventing conception. Another vaccine that is utilized is the peptide hCG is more specific to hCG and a more rapid and effective response occurs in the absence of LH, FSH, and TSH. ref name Markert In animals It is used to control populations of wild animals e.g. white tailed deer ref Remotely Delivered Immunocontraception in Captive White Tailed Deer, by John W. Turner, Jr., Irwin K. M. Liu and Jay F. Kirkpatrick Journal of Wildlife Management, 56 1 154 1992 http www.jstor.org pss 3808803 jstor ref or feral animals e.g. Mustang horse mustangs and also muntjac deer to control their population. ref Remotely Delivered Immunocontraception in Feral Horses, by Jay F. Kirkpatrick, Irwin K. M. Liu and John W. Turner, Jr. Wildlife Society Bulletin 18 326 330 1990 http www.jstor.org pss 3782221 JStor ref , because it is more humane th ... more details
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