For many people, hereinafter referred to as the DNA of the DNA is not strange, it is to bring the genetic code of life important carrier. But now, even so important carrier can also be synthetic material substitution.
British medical research council molecular biology laboratory agency, the researchers in the latest issue of the American journal of the journal science, the report said, they synthetic a substance called XNA, in many key function can substitute the DNA, and the study of the origin of life and even "artificial life" is of great significance.
DNA double helix structure has, by two of the reverse parallel more nucleotide chain mutual winding formation. A simple example, this is just like the zip on clothes, the two chain composition, each chain has used to each other the chain tooth and carrying bite chain tooth cloth. In the DNA of the chain, chain tooth is some bases, and carrying them by sugar and the bracket of the molecular structure of phosphoric acid.
Researchers said XNA can also like DNA genetic information storage. Because it used the "chain teeth, also is the base and the DNA, therefore XNA chain and the DNA chain between can also with each other, realize the genetic information transfer.
In the experiment, the researchers will a DNA chain of the genetic information transfer to XNA, then back again another chain DNA, the genetic information transmission accuracy is as high as 95% above. In addition, if meet some of the premise condition, part XNA in a test tube can also polymers such as DNA as evolve into different forms.
One of the architects of the report HuoLiGe Philip said, the experiment result XNA has two key function of DNA, the genetic and evolve.
Artificial XNA in molecular form on and DNA is not exactly the same, show that the DNA is not necessarily carry life in the genetic code of the only carrier. Have a point of view that, the creatures of the earth are all use DNA to carries the genetic information, is because the earth at the beginning of the origin of life, the environment of the corresponding types of molecular number is rich. And in other places in the universe, maybe there was not the same genetic way life form.
The study also is thought to be in the "artificial life" an important step forward on the road, but some experts think the, human use of genetic information to artificial XNA and create a new life, still have a long way to go.
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对许多人来说，简称DNA的脱氧核糖核酸并不陌生，它是携带生命遗传密码的重要载体。但如今，即便如此重要的载体也能被人工合成的物质替代了。
英国医学研究委员会分子生物学实验室等机构的研究人员在最新一期美国《科学》杂志上发表报告说，他们人工合成了一种名为XNA的物质，在许多关键功能上可替代DNA，这对研究生命起源乃至“人造生命”具有重大意义。
DNA拥有双螺旋结构，由两条反向平行的多核甘酸链相互缠绕形成。打个简单的比方，这就像衣服上的拉链，由两个链条组成，每个链条上有用于相互咬合的链齿和承载链齿的布条。在DNA的链条中，链齿是一些碱基，而承载它们的支架由糖类和磷酸分子组成。
据研究人员介绍，XNA也能像DNA一样存储遗传信息。由于它所用的“链齿”，也就是碱基，和DNA中的一样，因此XNA链条和DNA链条之间还可互相结合，实现遗传信息的传递。
在实验中，研究人员将一个DNA链条上的遗传信息传递到XNA上，随后再传回另一个DNA链条，遗传信息传递的准确度高达95%以上。此外，如果满足一些前提条件，部分XNA聚合物在试管中还能如DNA一样进化成不同形态。
报告的作者之一菲利普·霍利格说，上述实验结果说明XNA已拥有DNA的两个关键功能——遗传和进化。
人造的XNA在分子构成上与DNA并不完全相同，这说明DNA不一定是携带生命遗传密码的唯一载体。有观点因此认为，地球上的生物之所以都采用了DNA来携带遗传信息，是因为地球生命起源之初，环境中相应种类的分子数量较丰富。而在宇宙中其他地方，也许存在遗传方式不相同的生命形式。
这项研究还被认为是在“人造生命”道路上迈出的重要一步，不过有专家认为，人类使用XNA来人工编制遗传信息并创造一种新生命，还有很长的路要走。
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