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此词条暂由彩云小译翻译，翻译字数共1157，未经人工整理和审校，带来阅读不便，请见谅。

{{Use dmy dates|date=July 2018}}

{{Use dmy dates|date=July 2018}}

[[File:GNA-T_vs._natural_DNA-T.png|thumb|[[Glycol nucleic acid]] ''(left)'' is an example of a xeno nucleic acid because it has a different backbone than DNA ''(right)''.]]

[[File:GNA-T_vs._natural_DNA-T.png|thumb|[[Glycol nucleic acid]] ''(left)'' is an example of a xeno nucleic acid because it has a different backbone than DNA ''(right)''.|链接=Special:FilePath/GNA-T_vs._natural_DNA-T.png]]

'''Xeno nucleic acids''' ('''XNA''') are synthetic [[nucleic acid analogue]]s that have a different sugar backbone than the natural nucleic acids [[DNA]] and [[RNA]].<ref name="Schmidt2012">{{cite book |last=Schmidt|first=Markus | name-list-style = vanc |title=Synthetic Biology |url=https://books.google.com/books?id=lr0SgX1Hx2gC&pg=PA151|access-date=9 May 2013|year= 2012|publisher=John Wiley & Sons|isbn=978-3-527-65926-5|pages=151–}}</ref> As of 2011, at least six types of synthetic sugars have been shown to form nucleic acid backbones that can store and retrieve genetic information. Research is now being done to create synthetic polymerases to transform XNA. The study of its production and application has created a field known as [[xenobiology]].

'''Xeno nucleic acids''' ('''XNA''') are synthetic [[nucleic acid analogue]]s that have a different sugar backbone than the natural nucleic acids [[DNA]] and [[RNA]].<ref name="Schmidt2012">{{cite book |last=Schmidt|first=Markus | name-list-style = vanc |title=Synthetic Biology |url=https://books.google.com/books?id=lr0SgX1Hx2gC&pg=PA151|access-date=9 May 2013|year= 2012|publisher=John Wiley & Sons|isbn=978-3-527-65926-5|pages=151–}}</ref> As of 2011, at least six types of synthetic sugars have been shown to form nucleic acid backbones that can store and retrieve genetic information. Research is now being done to create synthetic polymerases to transform XNA. The study of its production and application has created a field known as [[xenobiology]].

Xeno nucleic acids (XNA) are synthetic nucleic acid analogues that have a different sugar backbone than the natural nucleic acids DNA and RNA. As of 2011, at least six types of synthetic sugars have been shown to form nucleic acid backbones that can store and retrieve genetic information. Research is now being done to create synthetic polymerases to transform XNA. The study of its production and application has created a field known as xenobiology.

Xeno nucleic acids (XNA) are synthetic nucleic acid analogues that have a different sugar backbone than the natural nucleic acids DNA and RNA. As of 2011, at least six types of synthetic sugars have been shown to form nucleic acid backbones that can store and retrieve genetic information. Research is now being done to create synthetic polymerases to transform XNA. The study of its production and application has created a field known as xenobiology.

Although the genetic information is still stored in the four canonical base pairs (unlike other [[nucleic acid analogues]]), natural DNA polymerases cannot read and duplicate this information. Thus the genetic information stored in XNA is "invisible" and therefore useless to natural DNA-based organisms.<ref name="Schmidt1">{{cite journal | vauthors = Schmidt M | title = Xenobiology: a new form of life as the ultimate biosafety tool | journal = BioEssays | volume = 32 | issue = 4 | pages = 322–331 | date = April 2010 | pmid = 20217844 | pmc = 2909387 | doi = 10.1002/bies.200900147 }}</ref>

Although the genetic information is still stored in the four canonical base pairs (unlike other [[nucleic acid analogues]]), natural DNA polymerases cannot read and duplicate this information. Thus the genetic information stored in XNA is "invisible" and therefore useless to natural DNA-based organisms.<ref name="Schmidt1">{{cite journal | vauthors = Schmidt M | title = Xenobiology: a new form of life as the ultimate biosafety tool | journal = BioEssays | volume = 32 | issue = 4 | pages = 322–331 | date = April 2010 | pmid = 20217844 | pmc = 2909387 | doi = 10.1002/bies.200900147 }}</ref>

Although the genetic information is still stored in the four canonical base pairs (unlike other nucleic acid analogues), natural DNA polymerases cannot read and duplicate this information. Thus the genetic information stored in XNA is "invisible" and therefore useless to natural DNA-based organisms.

Although the genetic information is still stored in the four canonical base pairs (unlike other nucleic acid analogues), natural DNA polymerases cannot read and duplicate this information. Thus the genetic information stored in XNA is "invisible" and therefore useless to natural DNA-based organisms.

虽然遗传信息仍然存储在四个典型的碱基对(不像其他核酸类似物) ，自然的 DNA 聚合酶不能读取和复制这些信息。因此，存储在 XNA 中的遗传信息是“看不见的”，因此对于天然的 dna 为基础的生物体来说是无用的。

虽然遗传信息仍然存储在四个标准碱基对(不像其他核酸类似物) ，但是天然的DNA聚合酶不能读取和复制这些信息。因此，存储在XNA中的遗传信息是“不可视的”，对于以天然DNA为基础的生物体来说是无用的。

==Background==

==Background==

The structure of DNA was discovered in 1953. Around the early 2000s, researchers created a number of exotic DNA-like structures, XNA. XNA is a synthetic polymer that can carry the same information as DNA, but with different molecular constituents. The "X" in XNA stands for "xeno," meaning stranger or alien, indicating the difference in the molecular structure as compared to DNA or RNA.

The structure of DNA was discovered in 1953. Around the early 2000s, researchers created a number of exotic DNA-like structures, XNA. XNA is a synthetic polymer that can carry the same information as DNA, but with different molecular constituents. The "X" in XNA stands for "xeno," meaning stranger or alien, indicating the difference in the molecular structure as compared to DNA or RNA.

Not much was done with XNA until the development of special polymerase [[enzyme]], capable of copying XNA from a DNA template as well as copying XNA back into DNA.<ref name=":1">{{Cite web |last=Gonzales |first=Robbie | name-list-style = vanc |title=XNA Is Synthetic DNA That's Stronger than the Real Thing |website=[[Io9]] |date=19 April 2012 |access-date=15 October 2015 |url=http://io9.com/5903221/meet-xna-the-first-synthetic-dna-that-evolves-like-the-real-thing}}</ref> Pinheiro et al. (2012), for example, has demonstrated such an XNA-capable polymerase that works on sequences of ~100bp in length.<ref name="Synthetic genetic polymers capable">{{cite journal | vauthors = Pinheiro VB, Taylor AI, Cozens C, Abramov M, Renders M, Zhang S, Chaput JC, Wengel J, Peak-Chew SY, McLaughlin SH, Herdewijn P, Holliger P | display-authors = 6 | title = Synthetic genetic polymers capable of heredity and evolution | journal = Science | volume = 336 | issue = 6079 | pages = 341–344 | date = April 2012 | pmid = 22517858 | pmc = 3362463 | doi = 10.1126/science.1217622 | bibcode = 2012Sci...336..341P }}</ref> More recently, synthetic biologists [[Philipp Holliger]] and Alexander Taylor managed to create XNAzymes, the XNA equivalent of a [[ribozyme]], enzymes made of DNA or ribonucleic acid. This demonstrates that XNAs not only store hereditary information, but can also serve as enzymes, raising the possibility that life elsewhere could have begun with something other than RNA or DNA.<ref>{{Cite web |website=[[Medical Research Council (United Kingdom)|Medical Research Council]] |title=World's first artificial enzymes created using synthetic biology |date=1 December 2014 |url=http://www.mrc.ac.uk/news/browse/world-s-first-artificial-enzymes-created-using-synthetic-biology/}}</ref>

Not much was done with XNA until the development of special polymerase [[enzyme]], capable of copying XNA from a DNA template as well as copying XNA back into DNA.<ref name=":1">{{Cite web |last=Gonzales |first=Robbie | name-list-style = vanc |title=XNA Is Synthetic DNA That's Stronger than the Real Thing |website=[[Io9]] |date=19 April 2012 |access-date=15 October 2015 |url=http://io9.com/5903221/meet-xna-the-first-synthetic-dna-that-evolves-like-the-real-thing}}</ref> Pinheiro et al. (2012), for example, has demonstrated such an XNA-capable polymerase that works on sequences of ~100bp in length.<ref name="Synthetic genetic polymers capable">{{cite journal | vauthors = Pinheiro VB, Taylor AI, Cozens C, Abramov M, Renders M, Zhang S, Chaput JC, Wengel J, Peak-Chew SY, McLaughlin SH, Herdewijn P, Holliger P | display-authors = 6 | title = Synthetic genetic polymers capable of heredity and evolution | journal = Science | volume = 336 | issue = 6079 | pages = 341–344 | date = April 2012 | pmid = 22517858 | pmc = 3362463 | doi = 10.1126/science.1217622 | bibcode = 2012Sci...336..341P }}</ref> More recently, synthetic biologists [[Philipp Holliger]] and Alexander Taylor managed to create XNAzymes, the XNA equivalent of a [[ribozyme]], enzymes made of DNA or ribonucleic acid. This demonstrates that XNAs not only store hereditary information, but can also serve as enzymes, raising the possibility that life elsewhere could have begun with something other than RNA or DNA.<ref>{{Cite web |website=[[Medical Research Council (United Kingdom)|Medical Research Council]] |title=World's first artificial enzymes created using synthetic biology |date=1 December 2014 |url=http://www.mrc.ac.uk/news/browse/world-s-first-artificial-enzymes-created-using-synthetic-biology/}}</ref>

Not much was done with XNA until the development of special polymerase enzyme, capable of copying XNA from a DNA template as well as copying XNA back into DNA. Pinheiro et al. (2012), for example, has demonstrated such an XNA-capable polymerase that works on sequences of ~100bp in length. More recently, synthetic biologists Philipp Holliger and Alexander Taylor managed to create XNAzymes, the XNA equivalent of a ribozyme, enzymes made of DNA or ribonucleic acid. This demonstrates that XNAs not only store hereditary information, but can also serve as enzymes, raising the possibility that life elsewhere could have begun with something other than RNA or DNA.

Not much was done with XNA until the development of special polymerase enzyme, capable of copying XNA from a DNA template as well as copying XNA back into DNA. Pinheiro et al. (2012), for example, has demonstrated such an XNA-capable polymerase that works on sequences of ~100bp in length. More recently, synthetic biologists Philipp Holliger and Alexander Taylor managed to create XNAzymes, the XNA equivalent of a ribozyme, enzymes made of DNA or ribonucleic acid. This demonstrates that XNAs not only store hereditary information, but can also serve as enzymes, raising the possibility that life elsewhere could have begun with something other than RNA or DNA.

== Structure ==

== Structure ==

[[File:Sugars of DNA and XNA.jpeg|thumb|369x369px|This image displays the differences in the sugar backbones used in XNAs compared to common and biologically used DNA and RNA.]]

[[File:Sugars of DNA and XNA.jpeg|thumb|369x369px|This image displays the differences in the sugar backbones used in XNAs compared to common and biologically used DNA and RNA.|链接=Special:FilePath/Sugars_of_DNA_and_XNA.jpeg]]

Strands of DNA and RNA are formed by stringing together long chains of molecules called [[nucleotide]]s. A [[nucleotide]] is made up of three chemical components: a [[phosphate]], a five-carbon sugar group (this can be either a [[deoxyribose]] sugar—which gives us the "D" in DNA—or a [[ribose]] sugar—the "R" in RNA), and one of five standard bases ([[adenine]], [[guanine]], [[cytosine]], [[thymine]] or [[uracil]]).

Strands of DNA and RNA are formed by stringing together long chains of molecules called [[nucleotide]]s. A [[nucleotide]] is made up of three chemical components: a [[phosphate]], a five-carbon sugar group (this can be either a [[deoxyribose]] sugar—which gives us the "D" in DNA—or a [[ribose]] sugar—the "R" in RNA), and one of five standard bases ([[adenine]], [[guanine]], [[cytosine]], [[thymine]] or [[uracil]]).

Strands of DNA and RNA are formed by stringing together long chains of molecules called nucleotides. A nucleotide is made up of three chemical components: a phosphate, a five-carbon sugar group (this can be either a deoxyribose sugar—which gives us the "D" in DNA—or a ribose sugar—the "R" in RNA), and one of five standard bases (adenine, guanine, cytosine, thymine or uracil).

Strands of DNA and RNA are formed by stringing together long chains of molecules called nucleotides. A nucleotide is made up of three chemical components: a phosphate, a five-carbon sugar group (this can be either a deoxyribose sugar—which gives us the "D" in DNA—or a ribose sugar—the "R" in RNA), and one of five standard bases (adenine, guanine, cytosine, thymine or uracil).

这张图片显示了转录因子中使用的糖骨与常见的生物学使用的 DNA 和 RNA 的不同之处。DNA 链和 RNA 链是由称为核苷酸的长链分子串联而成的。一个核苷酸由三种化学成分组成: 一种是磷酸盐，一种是五碳糖基(这可以是脱氧核糖糖，它在 dna 中给我们提供了“ d”，也可以是核糖糖，即 RNA 中的“ r”) ，以及五种标准碱基之一(腺嘌呤、鸟嘌呤、胞嘧啶、胸腺嘧啶或尿嘧啶)。

这张图片显示了XNAs中使用的糖骨架与常见生物学上使用的DNA和RNA之间的差异。DNA链和RNA 链是由称为核苷酸的长链分子串联而成的。一个核苷酸由三种化学成分组成: 一种是磷酸盐，一种是五碳糖基(这可以是脱氧核糖糖，它在 dna 中给我们提供了“ d”，也可以是核糖糖，即 RNA 中的“ r”) ，以及五种标准碱基之一(腺嘌呤、鸟嘌呤、胞嘧啶、胸腺嘧啶或尿嘧啶)。

The molecules that piece together to form the six xeno nucleic acids are almost identical to those of DNA and RNA, with one exception: in XNA [[nucleotide]]s, the [[deoxyribose]] and [[ribose]] sugar groups of DNA and RNA have been replaced with other chemical structures. These substitutions make XNAs functionally and structurally analogous to DNA and RNA despite being unnatural and artificial.

The molecules that piece together to form the six xeno nucleic acids are almost identical to those of DNA and RNA, with one exception: in XNA [[nucleotide]]s, the [[deoxyribose]] and [[ribose]] sugar groups of DNA and RNA have been replaced with other chemical structures. These substitutions make XNAs functionally and structurally analogous to DNA and RNA despite being unnatural and artificial.