वायरस

विकिपीडिया से
(वाइरस से अनुप्रेषित)
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"Rotavirus"
रोटावायरस
वायरस बर्गीकरण e
(बिना रैंक कइल): वायरस
बर्गीकरण

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वायरस चाहे वाइरस (अंगरेजी: Virus) बहुत सूछ्म आकार के रोगकारी होलें जे इन्फेक्शन करे लें आ कौनों जिंदा जीवधारी के कोशिका (सेल) में आपन संख्या बढ़ावे लें। वायरस सभ कौनो भी किसिम के जीवधारी के शरीर में प्रवेश क के इन्फेक्शन क सके लें, एह में जानवर आ पेड़-पौधा से ले के सूछ्मजीव सभ जइसे कि बैक्टीरिया आ आर्काइया भी शामिल बाड़ें जे इनहना से परभावित हो सके लें।[1]

जब दमित्री इवानोव्सकी के 1892 के लेख में बैक्टीरिया के अलावा दुसरे किसिम के रोगकारी के बारे में छपल जवना से तमाकू के पौधा परभावित होखे आ एकरे बाद मार्टिनस बेइजरिंक 1898 में टोबैको मोजैक वायरस के पहिचान कइलें[2] तबसे ले के अबतक ले 5,000 से बेसी वायरस प्रजाति सभ के बिस्तृत बिबरन दिहल जा चुकल बाटे,[3] जबकि पर्यावरण में कई लाख किसिम के वायरस मौजूद बाड़ें।[4] वायरस पृथ्वी के लगभग हर किसिम के इकोसिस्टम में पावल जालें आ ई जीव जगत के सदस्य सभ में सभसे बेसी के संख्या वाला प्रकार हवे।[5][6] वायरस के अध्ययन करे वाली शाखा के वाइरोलॉजी भा वायरोलॉजी कहल जाला जे माइकोबायोलॉजी (सूछ्मजीवबिज्ञान) के उपशाखा हवे।

बर्गीकरण[संपादन]

Classification seeks to describe the diversity of viruses by naming and grouping them on the basis of similarities. In 1962, André Lwoff, Robert Horne, and Paul Tournier were the first to develop a means of virus classification, based on the Linnaean hierarchical system.[7] This system based classification on phylum, class, order, family, genus, and species. Viruses were grouped according to their shared properties (not those of their hosts) and the type of nucleic acid forming their genomes.[8] In 1966, the International Committee on Taxonomy of Viruses (ICTV) was formed. The system proposed by Lwoff, Horne and Tournier was never fully accepted by the ICTV because small genome size viruses and their high rate of mutation makes it difficult to determine their ancestry beyond order. As such, the Baltimore classification is used to supplement the more traditional hierarchy.[9]

ICTV classification[संपादन]

The International Committee on Taxonomy of Viruses (ICTV) developed the current classification system and wrote guidelines that put a greater weight on certain virus properties to maintain family uniformity. A unified taxonomy (a universal system for classifying viruses) has been established. Only a small part of the total diversity of viruses has been studied.[10]

The general taxonomic structure of taxon ranges actually used (as of November 2018) is as follows:

Phylum (-viricota)
Subphylum (-viricotina)
Class (-viricetes)
Order (-virales)
Suborder (-virineae)
Family (-viridae)
Subfamily (-virinae)
Genus (-virus)
Subgenus (-virus)
Species

As of 2018, 14 orders, 143 families, 64 subfamilies, 846 genera, and 4,958 species of viruses have been defined by the ICTV.[11] The orders are the Caudovirales, Herpesvirales, Ligamenvirales, Mononegavirales, Nidovirales, Ortervirales, Picornavirales, Bunyavirales, Tymovirales, Muvirales, Serpentovirales, Jingchuvirales, Goujianvirales, and Articulavirales.[12]

Baltimore classification[संपादन]

A diagram showing how the Baltimore Classification is based on a virus's DNA or RNA and method of mRNA synthesis
The Baltimore Classification of viruses is based on the method of viral mRNA synthesis

The Nobel Prize-winning biologist David Baltimore devised the Baltimore classification system.[13][14] The ICTV classification system is used in conjunction with the Baltimore classification system in modern virus classification.[15][16][17]

The Baltimore classification of viruses is based on the mechanism of mRNA production. Viruses must generate mRNAs from their genomes to produce proteins and replicate themselves, but different mechanisms are used to achieve this in each virus family. Viral genomes may be single-stranded (ss) or double-stranded (ds), RNA or DNA, and may or may not use reverse transcriptase (RT). In addition, ssRNA viruses may be either sense (+) or antisense (−). This classification places viruses into seven groups:


As an example of viral classification, the chicken pox virus, varicella zoster (VZV), belongs to the order Herpesvirales, family Herpesviridae, subfamily Alphaherpesvirinae, and genus Varicellovirus. VZV is in Group I of the Baltimore Classification because it is a dsDNA virus that does not use reverse transcriptase.

The complete set of viruses in an organism or habitat is called the virome; for example, all human viruses constitute the human virome.[18]

संदर्भ[संपादन]

  1. Koonin EV, Senkevich TG, Dolja VV. The ancient Virus World and evolution of cells. Biology Direct. 2006;1:29. doi:10.1186/1745-6150-1-29. PMID 16984643.
  2. Dimmock p. 4
  3. Dimmock p. 49
  4. Breitbart M. Here a virus, there a virus, everywhere the same virus?. Trends in Microbiology. 2005;13(6):278–84. doi:10.1016/j.tim.2005.04.003. PMID 15936660.
  5. Lawrence CM, Menon S, Eilers BJ, et al.. Structural and functional studies of archaeal viruses. The Journal of Biological Chemistry. 2009;284(19):12599–603. doi:10.1074/jbc.R800078200. PMID 19158076.
  6. Edwards RA, Rohwer F. Viral metagenomics. Nature Reviews Microbiology. 2005;3(6):504–10. doi:10.1038/nrmicro1163. PMID 15886693.
  7. Lwoff A, Horne RW, Tournier P. A virus system. Comptes rendus hebdomadaires des séances de l'Académie des sciences. 1962;254:4225–27. French. PMID 14467544.
  8. Lwoff A, Horne R, Tournier P. A system of viruses. Cold Spring Harbor Symposia on Quantitative Biology. 1962;27:51–55. doi:10.1101/sqb.1962.027.001.008. PMID 13931895.
  9. International Committee on Taxonomy of Viruses and the 3,142 unassigned species. Virology Journal. August 2005;2:64. doi:10.1186/1743-422X-2-64. PMID 16105179.
  10. Delwart EL. Viral metagenomics. Reviews in Medical Virology. 2007;17(2):115–31. doi:10.1002/rmv.532. PMID 17295196.
  11. ICTV Virus Taxonomy ICTV Virus Taxonomy Release History
  12. Taxonomy. en.
  13. उद्धरण खराबी:Invalid <ref> tag; no text was provided for refs named pmid4348509
  14. Baltimore D. The strategy of RNA viruses. Harvey Lectures. 1974;70 Series:57–74. PMID 4377923.
  15. van Regenmortel MH, Mahy BW. Emerging issues in virus taxonomy. Emerging Infectious Diseases. 2004;10(1):8–13. doi:10.3201/eid1001.030279. PMID 15078590.
  16. Mayo MA. Developments in plant virus taxonomy since the publication of the 6th ICTV Report. International Committee on Taxonomy of Viruses. Archives of Virology. 1999;144(8):1659–66. doi:10.1007/s007050050620. PMID 10486120.
  17. de Villiers EM, Fauquet C, Broker TR, Bernard HU, zur Hausen H. Classification of papillomaviruses. Virology. 2004;324(1):17–27. doi:10.1016/j.virol.2004.03.033. PMID 15183049.
  18. An Ecological Framework of the Human Virome Provides Classification of Current Knowledge and Identifies Areas of Forthcoming Discovery. The Yale Journal of Biology and Medicine. 2016;89(3):339–51. PMID 27698618.

स्रोत ग्रंथ[संपादन]

  • Collier, Leslie; Balows, Albert; Sussman, Max (1998) Topley and Wilson's Microbiology and Microbial Infections ninth edition, Volume 1, Virology, volume editors: Mahy, Brian and Collier, Leslie. Arnold. ISBN 0-340-66316-2.
  • Dimmock, N.J; Easton, Andrew J; Leppard, Keith (2007) Introduction to Modern Virology sixth edition, Blackwell Publishing, ISBN 1-4051-3645-6.
  • Knipe, David M; Howley, Peter M; Griffin, Diane E; Lamb, Robert A; Martin, Malcolm A; Roizman, Bernard; Straus Stephen E. (2007) Fields Virology, Lippincott Williams & Wilkins. ISBN 0-7817-6060-7.
  • Shors, Teri (2008). Understanding Viruses. Jones and Bartlett Publishers. ISBN 0-7637-2932-9.