Sperm - wikipedia Sperm For other uses, see Sperm ( disambiguation ). Diagram of a human sperm cell Sperm is the male reproductive cell and is derived from the Greek word ( σπέρμα ) sperma ( meaning `` seed '' ). In the types of sexual reproduction known as anisogamy and its subtype oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the `` male '' or sperm cell. A uniflagellar sperm cell that is motile is referred to as a spermatozoon, whereas a non-motile sperm cell is referred to as a spermatium. Sperm cells can not divide and have a limited life span, but after fusion with egg cells during fertilization, a new organism begins developing, starting as a totipotent zygote. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. In mammals, sperm develops in the testicles, stored in the epididymis, and is released from the penis. Play media Video of human sperm cells recorded by an affordable home microscope. Contents 1 Sperm in animals 1.1 Function 1.2 Anatomy 1.3 Origin 1.4 Sperm quality 1.5 Sperm size 1.6 Market for human sperm 1.7 History 1.8 Forensic analysis 2 Sperm in plants 3 Motile sperm cells 4 Non-motile sperm cells 5 Sperm nuclei 6 Sperm centrioles 7 Sperm tail formation 8 See also 9 References 10 External links Sperm in animals Further information : Spermatozoon Function The main sperm function is to reach the ovum and fuse with it to deliver two sub-cellular structures : ( i ) the male pronucleus that contains the genetic material and ( ii ) the centrioles that are structures that help organize the microtubule cytoskeleton. Anatomy Sperm and egg fusing The mammalian sperm cell consists of a head, neck, a midpiece and a tail. The head contains the nucleus with densely coiled chromatin fibres, surrounded anteriorly by an acrosome, which contains enzymes used for penetrating the female egg. The neck contains the sperm centriole. The midpiece has a central filamentous core with many mitochondria spiralled around it, used for ATP production for the journey through the female cervix, uterus and uterine tubes. The tail or `` flagellum '' executes the lashing movements that propel the spermatocyte. During fertilization, the sperm provides three essential parts to the oocyte : ( 1 ) a signalling or activating factor, which causes the metabolically dormant oocyte to activate ; ( 2 ) the haploid paternal genome ; ( 3 ) the centriole, which is responsible for forming the centrosome and microtubule system. Origin The spermatozoa of animals are produced through spermatogenesis inside the male gonads ( testicles ) via meiotic division. The initial spermatozoon process takes around 70 days to complete. The spermatid stage is where the sperm develops the familiar tail. The next stage where it becomes fully mature takes around 60 days when it is called a spermatozoan. Sperm cells are carried out of the male body in a fluid known as semen. Human sperm cells can survive within the female reproductive tract for more than 5 days post coitus. Semen is produced in the seminal vesicles, prostate gland and urethral glands. In 2016 scientists at Nanjing Medical University claimed they had produced cells resembling mouse spermatids artificially from stem cells. They injected these spermatids into mouse eggs and produced pups. Sperm quality Human sperm stained for semen quality testing. Main article : Semen quality Sperm quantity and quality are the main parameters in semen quality, which is a measure of the ability of semen to accomplish fertilization. Thus, in humans, it is a measure of fertility in a man. The genetic quality of sperm, as well as its volume and motility, all typically decrease with age. ( See paternal age effect. ) DNA damages present in sperm cells in the period after meiosis but before fertilization may be repaired in the fertilized egg, but if not repaired, can have serious deleterious effects on fertility and the developing embryo. Human sperm cells are particularly vulnerable to free radical attack and the generation of oxidative DNA damage. ( see e.g. 8 - Oxo - 2 ' - deoxyguanosine ) The postmeiotic phase of mouse spermatogenesis is very sensitive to environmental genotoxic agents, because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. Irradiation of male mice during late spermatogenesis can induce damage that persists for at least 7 days in the fertilizing sperm cells, and disruption of maternal DNA double - strand break repair pathways increases sperm cell - derived chromosomal aberrations. Treatment of male mice with melphalan, a bifunctional alkylating agent frequently employed in chemotherapy, induces DNA lesions during meiosis that may persist in an unrepaired state as germ cells progress though DNA repair - competent phases of spermatogenic development. Such unrepaired DNA damages in sperm cells, after fertilization, can lead to offspring with various abnormalities. Sperm size Related to sperm quality is sperm size, at least in some animals. For instance, the sperm of some species of fruit fly ( Drosophila ) are up to 5.8 cm long -- about 20 times as long as the fly itself. Longer sperm cells are better than their shorter counterparts at displacing competitors from the female 's seminal receptacle. The benefit to females is that only healthy males carry ' good ' genes that can produce long sperm in sufficient quantities to outcompete their competitors. Market for human sperm Further information : Sperm donation Some sperm banks hold up to 170 litres ( 37 imp gal ; 45 US gal ) of sperm. In addition to ejaculation, it is possible to extract sperm through TESE. On the global market, Denmark has a well - developed system of human sperm export. This success mainly comes from the reputation of Danish sperm donors for being of high quality and, in contrast with the law in the other Nordic countries, gives donors the choice of being either anonymous or non-anonymous to the receiving couple. Furthermore, Nordic sperm donors tend to be tall and highly educated and have altruistic motives for their donations, partly due to the relatively low monetary compensation in Nordic countries. More than 50 countries worldwide are importers of Danish sperm, including Paraguay, Canada, Kenya, and Hong Kong. However, the Food and Drug Administration ( FDA ) of the US has banned import of any sperm, motivated by a risk of transmission of Creutzfeldt -- Jakob disease, although such a risk is insignificant, since artificial insemination is very different from the route of transmission of Creutzfeldt -- Jakob disease. The prevalence of Creutzfeldt -- Jakob disease for donors is at most one in a million, and if the donor was a carrier, the infectious proteins would still have to cross the blood - testis barrier to make transmission possible. History See also : Homunculus § Homunculus of spermists Sperm were first observed in 1677 by Antonie van Leeuwenhoek using a microscope, he described them as being animalcules ( little animals ), probably due to his belief in preformationism, which thought that each sperm contained a fully formed but small human. Forensic analysis Ejaculated fluids are detected by ultraviolet light, irrespective of the structure or colour of the surface. Sperm heads, e.g. from vaginal swabs, are still detected by microscopy using the `` Christmas Tree Stain '' method, i.e., Kernechtrot - Picroindigocarmine ( KPIC ) staining. Sperm in plants Sperm cells in algal and many plant gametophytes are produced in male gametangia ( antheridia ) via mitotic division. In flowering plants, sperm nuclei are produced inside pollen. Motile sperm cells Motile sperm cells of algae and seedless plants. Motile sperm cells typically move via flagella and require a water medium in order to swim toward the egg for fertilization. In animals most of the energy for sperm motility is derived from the metabolism of fructose carried in the seminal fluid. This takes place in the mitochondria located in the sperm 's midpiece ( at the base of the sperm head ). These cells can not swim backwards due to the nature of their propulsion. The uniflagellated sperm cells ( with one flagellum ) of animals are referred to as spermatozoa, and are known to vary in size. Motile sperm are also produced by many protists and the gametophytes of bryophytes, ferns and some gymnosperms such as cycads and ginkgo. The sperm cells are the only flagellated cells in the life cycle of these plants. In many ferns and lycophytes, they are multi-flagellated ( carrying more than one flagellum ). In nematodes, the sperm cells are amoeboid and crawl, rather than swim, towards the egg cell. Non-motile sperm cells Non-motile sperm cells called spermatia lack flagella and therefore can not swim. Spermatia are produced in a spermatangium. Because spermatia can not swim, they depend on their environment to carry them to the egg cell. Some red algae, such as Polysiphonia, produce non-motile spermatia that are spread by water currents after their release. The spermatia of rust fungi are covered with a sticky substance. They are produced in flask - shaped structures containing nectar, which attract flies that transfer the spermatia to nearby hyphae for fertilization in a mechanism similar to insect pollination in flowering plants. Fungal spermatia ( also called pycniospores, especially in the Uredinales ) may be confused with conidia. Conidia are spores that germinate independently of fertilization, whereas spermatia are gametes that are required for fertilization. In some fungi, such as Neurospora crassa, spermatia are identical to microconidia as they can perform both functions of fertilization as well as giving rise to new organisms without fertilization. Sperm nuclei In almost all embryophytes, including most gymnosperms and all angiosperms, the male gametophytes ( pollen grains ) are the primary mode of dispersal, for example via wind or insect pollination, eliminating the need for water to bridge the gap between male and female. Each pollen grain contains a spermatogenous ( generative ) cell. Once the pollen lands on the stigma of a receptive flower, it germinates and starts growing a pollen tube through the carpel. Before the tube reaches the ovule, the nucleus of the generative cell in the pollen grain divides and gives rise to two sperm nuclei, which are then discharged through the tube into the ovule for fertilization. In some protists, fertilization also involves sperm nuclei, rather than cells, migrating toward the egg cell through a fertilization tube. Oomycetes form sperm nuclei in a syncytical antheridium surrounding the egg cells. The sperm nuclei reach the eggs through fertilization tubes, similar to the pollen tube mechanism in plants. Sperm centrioles Most sperm cells have centrioles in the sperm neck. Sperm of many animals has 2 centrioles known as the proximal centriole and distal centriole. Some animals like human have a single centriole known as the proximal centriole. Mice and rat have no sperm centrioles. The fruit fly Drosophila melanogaster has a single centriole and an atypical centriole named the Proximal Centriole - Like ( PCL ). Sperm tail formation The sperm tail is a specialized type of cilium ( aka flagella ). In many animals the sperm tail is formed in a unique way, which is named Cytosolic ciliogenesis, since all or part of axoneme of the sperm tail is formed in the cytoplasm or get exposed to the cytoplasm. See also Mendelian inheritance Ejaculation Female sperm Female sperm storage Polyspermy Sperm competition Sperm donation Sperm granuloma Spermatogenesis Spermatozoon References Jump up ^ Ishijima, Sumio ; Oshio, Shigeru ; Mohri, Hideo ( 1986 ). `` Flagellar movement of human spermatozoa ''. Gamete Research. 13 ( 3 ) : 185 -- 197. doi : 10.1002 / mrd. 1120130302. Jump up ^ Hewitson, Laura & Schatten, Gerald P. ( 2003 ). `` The biology of fertilization in humans ''. In Patrizio, Pasquale et al. A color atlas for human assisted reproduction : laboratory and clinical insights. Lippincott Williams & Wilkins. p. 3. ISBN 978 - 0 - 7817 - 3769 - 2. Retrieved 2013 - 11 - 09. CS1 maint : Uses editors parameter ( link ) Jump up ^ Semen and sperm quality Jump up ^ Gould JE, Overstreet JW and Hanson FW ( 1984 ) `` Assessment of human sperm function after recovery from the female reproductive tract ''. Biology of Reproduction 31, 888 -- 894. Jump up ^ Cyranoski, David ( 25 February 2016 ). `` Researchers claim to have made artificial mouse sperm in a dish ''. Nature. doi : 10.1038 / nature. 2016.19453. Retrieved 4 March 2016. Jump up ^ Gurevich, Rachel ( 2008 - 06 - 10 ). `` Does Age Affect Male Fertility ? ''. About.com. Retrieved 14 February 2010. Jump up ^ Gavriliouk D, Aitken RJ ( 2015 ). `` Damage to Sperm DNA Mediated by Reactive Oxygen Species : Its Impact on Human Reproduction and the Health Trajectory of Offspring ''. Advances in Experimental Medicine and Biology. 868 : 23 -- 47. doi : 10.1007 / 978 - 3 - 319 - 18881 - 2_2. PMID 26178844. Jump up ^ Marchetti F, Wyrobek AJ ( 2008 ). `` DNA repair decline during mouse spermiogenesis results in the accumulation of heritable DNA damage ''. DNA Repair. 7 ( 4 ) : 572 -- 81. doi : 10.1016 / j. dnarep. 2007.12. 011. PMID 18282746. Jump up ^ Marchetti F, Essers J, Kanaar R, Wyrobek AJ ( 2007 ). `` Disruption of maternal DNA repair increases sperm - derived chromosomal aberrations ''. Proceedings of the National Academy of Sciences of the United States of America. 104 ( 45 ) : 17725 -- 9. doi : 10.1073 / pnas. 0705257104. PMC 2077046. PMID 17978187. Jump up ^ Marchetti F, Bishop J, Gingerich J, Wyrobek AJ ( 2015 ). `` Meiotic interstrand DNA damage escapes paternal repair and causes chromosomal aberrations in the zygote by maternal misrepair ''. Scientific Reports. 5 : 7689. doi : 10.1038 / srep07689. PMC 4286742. PMID 25567288. Jump up ^ Lüpold, Stefan ; Manier, Mollie K. ; Puniamoorthy, Nalini ; Schoff, Christopher ; Starmer, William T. ; Luepold, Shannon H. Buckley ; Belote, John M. ; Pitnick, Scott ( 2016 - 05 - 26 ). `` How sexual selection can drive the evolution of costly sperm ornamentation ''. Nature. 533 ( 7604 ) : 535 -- 538. doi : 10.1038 / nature18005. ISSN 1476 - 4687. PMID 27225128. Jump up ^ Gardiner, Jennifer R. ( 2016 - 05 - 26 ). `` Evolution : The bigger, the better ''. Nature. 533 ( 7604 ) : 476. doi : 10.1038 / 533476a. ISSN 1476 - 4687. PMID 27225117. Jump up ^ Sarfraz Manzoor ( 2 November 2012 ). `` Come inside : the world 's biggest sperm bank ''. The Guardian. Retrieved 4 August 2013. ^ Jump up to : Assisted Reproduction in the Nordic Countries ncbio.org ^ Jump up to : FDA Rules Block Import of Prized Danish Sperm Posted Aug 13, 08 7 : 37 AM CDT in World, Science & Health ^ Jump up to : Steven Kotler ( 26 September 2007 ). `` The God of Sperm ''. Jump up ^ `` Timeline : Assisted reproduction and birth control ''. CBC News. Retrieved 2006 - 04 - 06. Jump up ^ Anja Fiedler ; Mark Benecke ; et al. `` Detection of Semen ( Human and Boar ) and Saliva on Fabrics by a Very High Powered UV - / VIS - Light Source ''. Retrieved 2015 - 10 - 22. Jump up ^ Allery, J.P. ; Telmon, N. ; Mieusset, R. ; Blanc, A. ; Rougé, D. ( 2001 ). `` Cytological detection of spermatozoa : Comparison of three staining methods ''. Journal of forensic sciences. 46 ( 2 ) : 349 -- 351. PMID 11305439. Jump up ^ Illinois State Police / President 's DNA Initiative. `` The Presidents 's DNA Initiative : Semen Stain Identification : Kernechtrot '' ( PDF ). Retrieved 2009 - 12 - 10. ^ Jump up to : Raven, Peter H. ; Ray F. Evert ; Susan E. Eichhorn ( 2005 ). Biology of Plants, 7th Edition. New York : W.H. Freeman and Company Publishers. ISBN 0 - 7167 - 1007 - 2. Jump up ^ Bottino D, Mogilner A, Roberts T, Stewart M, Oster G ( 2002 ). `` How nematode sperm crawl ''. Journal of Cell Science. 115 ( Pt 2 ) : 367 -- 84. PMID 11839788. CS1 maint : Multiple names : authors list ( link ) Jump up ^ Sumbali, Geeta ( 2005 ). The Fungi. Alpha Science Int'l Ltd. ISBN 1 - 84265 - 153 - 6. Jump up ^ Maheshwari R ( 1999 ). `` Microconidia of Neurospora crassa ''. Fungal Genetics and Biology. 26 ( 1 ) : 1 -- 18. doi : 10.1006 / fgbi. 1998.1103. PMID 10072316. Jump up ^ Atypical centrioles during sexual reproduction. Avidor - Reiss T, Khire A, Fishman EL, Jo KH. Front Cell Dev Biol. 2015 Apr 1 ; 3 : 21. doi : 10.3389 / fcell. 2015.00021. Jump up ^ A proximal centriole - like structure is present in Drosophila spermatids and can serve as a model to study centriole duplication. Blachon S, Cai X, Roberts KA, Yang K, Polyanovsky A, Church A, Avidor - Reiss T. Genetics. 2009 May ; 182 ( 1 ) : 133 - 44. doi : 10.1534 / genetics. 109.101709. Jump up ^ Shared and Distinct Mechanisms of Compartmentalized and Cytosolic Ciliogenesis. Avidor - Reiss T, Leroux MR. Curr Biol. 2015 Dec 7 ; 25 ( 23 ) : R1143 - 50. doi : 10.1016 / j. cub. 2015.11. 001. http://0-resolver.ebscohost.com.carlson.utoledo.edu/openurl?sid=Entrez%3aPubMed&id=pmid%3a26654377&site=ftf-live External links The Great Sperm Race pdf Human Sperm Under a Microscope Wikimedia Commons has media related to Sperm. Preceded by None Stages of human development Sperm + Oocyte Succeeded by Zygote Retrieved from `` https://en.wikipedia.org/w/index.php?title=Sperm&oldid=815259917 '' Categories : Fertility Germ cells Reproductive system Mammal male reproductive system Semen Human male reproductive system Hidden categories : CS1 maint : Uses editors parameter CS1 maint : Multiple names : authors list Wikipedia indefinitely semi-protected pages All articles with unsourced statements Articles with unsourced statements from January 2011 Articles containing video clips Talk View source Contents About Wikipedia বাংলা Cymraeg Esperanto فارسی Gaeilge ગુજરાતી हिन्दी Ido Kiswahili Македонски मराठी مازِرونی Bahasa Melayu پنجابی پښتو Soomaaliga کوردی தமிழ் ไทย Türkçe Edit links This page was last edited on 13 December 2017, at 19 : 37. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. 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Question: where are the mitochondria located in the sperm
Answer: midpiece; midpiece; midpiece (at the base of the sperm head); midpiece