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基因修改的原理

来源:可可英语 编辑:Melody   可可英语APP下载 |  可可官方微信:ikekenet

Hey there! Welcome to Life Noggin!

嘿!欢迎来到脑洞大开的生命奇想!
While it may sound like science fiction, scientists now have an efficient, incredibly accurate way to edit the genes of any living creature, including humans'.
科学家们现在有了一种有效且十分准确的方法来编辑任何生物的基因,包括人类的。听起来像是科幻小说。
This technology is called CRISPR and is going to change both the way research is done and the way genetic diseases are treated.
这项技术被称为CRISPR,它将改变研究方式和遗传疾病的治疗方式。
But what exactly is it?
但它到底是什么呢?
Before we get into it, I know that many of you are looking to start YouTube channels of your own, and we want to thank Graphic Stock for sponsoring this video.
等会我们做深入了解。我知道你们很多人都想在YouTube上建立自己的频道,我们要感谢Graphic Stock对这段视频的赞助。
基因修改They have over 300,000 graphics, photos, vectors, and images to make your videos beautiful, and they have the largest unlimited download library on the Internet!
他们拥有超过30万的图像、照片、矢量和图片,可以让你的视频大放异彩,而且他们有互联网上最大的无限下载库!
Most websites charge for each image, and it can cost you up to $30 per image.
大多数网站对图片收费,一张图片的费用可高达30美元。
With Graphic Stock you get unlimited downloads with your membership.
有了Graphic Stock图片库的会员,你就可以无限下载。
Go to graphicstock.com/youtube, or click the link in the description, to get your exclusive 7-day free trial to GraphicStock.
点击graphicstock.com/youtube,或者点击描述区中的链接,你就可以获得GraphicStock长达7天的免费试用。
During your trial, you can download 140 pieces of content. Like this photo of the beach I'm currently chillin on.
在试用期间,您可以下载140条内容。这是我最近很喜欢的海滩的照片。
You can also sign up for the annual plan which only costs $99 a year.
你也可以办个年卡,只要99美元。
The best part is that your membership comes with a 100% royalty free agreement, so you'll never get sued by copyright holders!
最棒的是,你的会员资格是100%免版税的,所以你永远不会被版权所有者起诉!
Ok, let's get back to CRISPR...
好,让我们回到CRISPR…
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeat, which is quite the mouthful.
CRISPR指的是成簇规律间隔短回文重复,真够拗口的。
But simply put, it describes short sections of repeating DNA that occur within bacteria and some microorganisms.
简单地说,它是指细菌和一些微生物中重复DNA的一小部分。
And these sequences are vital to that organism's immune system.
这些序列对生物体的免疫系统至关重要。
See, if a virus invades a bacterial cell, that virus' genome, or complete set of DNA, contains the information to keep replicating.
如果病毒侵入细菌细胞,病毒的基因组,或整套DNA,包含了要复制的信息。
And if the bacterium wants to survive, that replication needs to stop.
如果细菌想存活,复制就需要停止。
And therefore, its immune system needs to destroy the viral genome.
因此,它的免疫系统需要破坏病毒基因组。
But how's that done?
但是这是怎么做的呢?
Well, between each repeating section of DNA, there are short sequences of DNA called spacers.
在DNA的每一个重复部分之间,有一些短DNA序列叫做间隔DNA。
And these form what can be thought of as a viral "most-wanted list" since they are the bacterium's way of remembering which viruses have previously attacked it.
这些结构可以被看作病毒的“通缉名单”,因为它们记忆了哪些病毒曾经攻击过该细菌。
So, when a virus invades a cell, if there is an associated spacer already there, meaning it's on the most-wanted list, the bacterium can go on to destroy the virus.
因此,当病毒侵入细胞时,如果有一个相关的间隔DNA已经存在,也就是说它在通缉名单上,细菌就可以破坏病毒。
But if the virus is new, DNA from it must first be inserted into the CRISPR sequence as a new spacer.
但是如果病毒是新的,它的DNA必须先被植入CRISPR序列形成一个新的间隔DNA。
And after this happens, the battle is ready to begin.
在这之后,战斗就开始了。
Once the virus has been identified, the DNA in the spacer is copied into an RNA molecule.
一旦病毒被识别出来,间隔DNA的DNA就被复制到一个RNA分子中。
And then the real magic begins when the cas enzymes, or CRISPR-associated proteins, take over.
然后真正魔幻的部分开始了,Cas酶,或者是与CRISPR相关的蛋白质,占了上风。
These are essentially the bacteria's tiny warriors, and the most famous of which is called Cas9.
这些其实都是细菌的小卫士,最著名的是Cas9。
These take up the RNA, and move them around the cell, until they encounter the virus that matches.
它们占领了RNA,并将它们移动到细胞周围,直到它们遇到匹配的病毒。
The cas enzyme then cuts the viral DNA in two, preventing it from replicating, and therefore, protecting the bacterium.
然后,Cas酶将病毒DNA切成两段,防止其复制,从而保护细菌。
So that's all well and good for bacteria, but how does it relate to other living creatures?
这对细菌来说很好,但与其他生物有什么关系呢?
Well, if a scientist wants to destroy or edit a part of the DNA sequence, in a human, let's say, all they have to do is design some RNA called guide RNA, wrap it up in some Cas9, and inject it into the cell.
如果一个科学家想要破坏或编辑人类DNA序列的一部分,他们只需要设计一个向导RNA,把它包裹在一些Cas9中,然后注入到细胞中。
This can be used to replace a faulty gene by cutting it out and putting a healthy version in its place.
这可以用来替代一个有缺陷的基因,把它剪掉,在原地放一个健康的基因。
Or it can be used to silence a gene as the DNA fails to attempt to repair itself completely.
或者DNA无法完全修复自己的时候,可以用这个方法来使基因静默。
Or it could be used to add a completely different gene entirely.
或者可以用来添加完全不同的基因。
Now, at this point, you can probably see the huge potential here.
这一点显示出了巨大潜力。
Scientists can begin to better understand genetic diseases, like cystic fibrosis, by isolating individual genes and seeing their effects.
通过分离个体基因并观察其影响,科学家们开始更深入地理解遗传疾病,如囊性纤维化。
And already, scientists have used this simple technique to create mosquitos that are resistant to malaria, help treat HIV and blindness, and even modify human embryos.
科学家们已经用这个简单的技术制造了一种蚊子,它可以抵抗疟疾,帮助治疗艾滋病和失明,甚至还可以修改人类胚胎。
Of course, this brings up the ethics of creating a "designer baby", but the technology is far from being used commercially.
当然,这也带来了制造“设计婴儿”的伦理道德问题,但这项技术还远远没有商业化。
So what do you think of all this?
你觉得怎么样?
Would you edit your genes to treat a disorder? or create a designer baby?
你会编辑你的基因来治疗疾病吗?会制造一个设计婴儿吗?
As always, I'm Blocko, this has been Life Noggin.
我是宝高,这里是脑洞大开的生命奇想。
Don't forget to keep on thinking.
思考不要停。

重点单词   查看全部解释    
copyright ['kɔpirait]

想一想再看

n. 版权,著作权
adj. 版权的

 
silence ['sailəns]

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n. 沉默,寂静
vt. 使安静,使沉默

 
bacteria [bæk'tiəriə]

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n. (复数)细菌

 
virus ['vaiərəs]

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n. 病毒,病原体

 
potential [pə'tenʃəl]

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adj. 可能的,潜在的
n. 潜力,潜能

 
sequence ['si:kwəns]

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n. 顺序,连续,次序,序列,一系列
vt.

联想记忆
ethics ['eθiks]

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n. 道德规范

联想记忆
exclusive [iks'klu:siv]

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adj. 独占的,唯一的,排外的
n. 独家新

联想记忆
vital ['vaitl]

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adj. 至关重要的,生死攸关的,有活力的,致命的

联想记忆
stock [stɔk]

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n. 存货,储备; 树干; 血统; 股份; 家畜

 

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