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这种病毒会感染...其它病毒

The Baffling Viruses That Infect... Other Viruses

这一集视频由NordVPN提供支持
This episode is supported by NordVPN.
目前 NordVPN为《科学秀》提供浏览器
Right now, NordVPN is offering SciShow viewers
给你一次建立自己虚拟网站的机会
a chance to set up your own Virtual Private
而且保护你的网上经历
Network and start protecting your internet experience today
一个持续3年的计划
with 77 % off a 3-year plan.
在NordVPN.com/SCISHOW网站 使用”SCISHOW”代码
Use the code “SCISHOW” at NordVPN. com/SCISHOW.
#音乐#
[♪INTRO]
病毒让人们生病
Viruses make so many people sick and miserable
似乎现在有了反转的机会
that it seems like turnabout—it ’ s only
这样才公平
fair play!
让病毒染病!
Make the viruses get sick for once!
听起来很荒谬 对吧?
But that’s ridiculous… right? Well,
或许不是
maybe not.
病毒感染病毒 噬病毒体 这都是真的
Virus-infecting viruses, or virophages, aretotally real, because evolution just doesn’t
因为进化没有停止
know when to quit.
第一个噬病毒体 命名为Sputnik
The first virophage, named Sputnik,
由一个法国研究团队在
was discovered in 2008 by a team of French researchers in
一个巴黎水塔于2008年发现
a Parisian water tower.
他们不仅发现了它
But they didn’t discover it alone.
我们知道的很多
Pretty much everything we learn
关于这些极小病毒都和
about these extremely small viruses is linked to the extremely
都和它们感染的大病毒有关 命名为巨病毒
big viruses they infect, called giant viruses.
由于巨病毒
And since giant viruses,
如咪咪病毒还有潘多拉病毒于2003年被发现
like mimiviruses and pandoraviruses, were only discovered in 2003,
这是一个全新的领域
this whole field is brand new territory.
发现巨病毒感染了阿米巴
Giant viruses were discovered infecting amoebas,
这一情况在世界各地都有出现
and have been found all over the world.
还不清楚它是否感染人
It ’ s not entirely clear whether they can make humans sick or not.
病毒已被多次从人身上分离出来
They ’ ve been isolated within humans a few times,
包括罹患肺炎的人们(身上也分离出了病毒)
including people sick with pneumonia,
但也不是很清楚
but it ’ s not 100 % clear
是否它们是致病因素 或仅仅是”过客”
if they were causing the illness or just hanging out.
相对来说 他们也太大了
And they’re huge… relatively speaking.
它们的外形和基因过大
In terms of their size and genetic complexity,
巨病毒和其他病毒相比的话
giant viruses are more like bacteria than
其实更像细菌
most other viruses. Like,
咪咪病毒大约500-800毫微米
mimiviruses are about 500 to 800 nanometers
基因组大约1200万
across and have genomes of around 12 million
碱基对
base pairs.
潘多拉病毒更大
And pandoraviruses are even bigger. Now,
咪咪病毒被伴侣噬病毒体捕食
mimiviruses are preyed upon by the Sputnik virophage,
伴侣噬病毒体只有50毫微米
which is only 50 nanometers across
它也只有18000碱基对
and has a genome of about 18,000 base pairs.
对于病毒来说也不小了
That’s actually not super small for a virus.
细菌感染病毒兰布达形状特殊
The bacteria-infecting virus lambda forms particles
尺寸和它差不多 感冒病毒
of a similar size, and the flu virus
实际上基因组更少
actually has a smaller genome.
奇怪的是 尽管巨病毒非常大
But what ’ s weird is that even though giant viruses are big,
似乎它们也不
it doesn ’ t seem like they
站在入侵者一方
should be able to support invaders.
尤其是噬病毒体也是病毒
Especially since virophages are still…viruses.
它们由碱基和蛋白组成
They ’ re made of DNA and protein,
但它们缺乏细胞复制的工具
but they lack all the cellular replication tools needed
没法复制DNA 以及合成蛋白质的转录工具
to copy DNA, and the translation tools neededto make proteins.
这就是为什么病毒需要宿主
That’s why viruses need hosts.
它们进入宿主细胞 拿过细胞设备 将宿主变成病毒工厂
They enter host cells and take over cellular equipment to make little virus factories.
没有宿主细胞 病毒没法复制
Without a host cell, viruses would never reproduce. And,
这样来说 宿主也变成了病毒
in this case, the hosts are…also viruses.
咪咪病毒不能独立复制DNA和蛋白质
Mimiviruses can’t copy DNA and protein on their own either,
需要靠感染变形虫来繁殖
and have to infect an amoeba to reproduce.
只要噬病毒体钻进去
That’s where the virophage sneaks in.
感染了咪咪病毒
It infects the mimivirus
它感染了阿米巴变成巨病毒工厂
while it ’ s infecting the amoeba and borrows the giant virus factory.
并不是要去复制更多巨病毒
So instead of making more giant viruses,
阿米巴炮制出大量噬病毒体
the amoeba churns out the virophage copies instead.
直接作用于巨病毒 它的作用就是复制病毒
This directly harms the giant virus and its efforts to reproduce,
这个使得
which is what leads
研究者认为 噬病毒体是巨病毒的寄生物 而不是阿米巴的
researchers to say that virophages are parasites of giant viruses, not of amoebas. Now,
巨病毒有些特殊
giant viruses are kind of special
因为它们好像有细胞设备
because they seem to have some of that cellular equipment,
像一些蛋白质转录的基因
like a few genes involved in protein translation.
它们没有核糖体
But they don ’ t have ribosomes,
真正组装蛋白质的工厂
the big factories that actually string proteins together.
所以它们没法独自完成工作
So they can’t get the job done all by themselves.
这也就是为什么许多的生物学家排斥病毒
That ’ s why many biologists exclude viruses
从生命树来看 包括细菌 古生菌
from the tree of life that includes bacteria, archaea,
还有真核生物
and eukaryotes.
如果病毒不能自我复制 它就不是真正的生物
If viruses can’t replicate on their own,they’re not really alive.
科学家比较不同的基因 去确定它们的进化关系
Scientists can compare various genes to determine evolutionary relationships,
但假如你想
but if you want
回到生命起源
to go back to the very beginning,
你必须用所有细胞生物都有的物质来比较
you have to compare something that all cellular life has.
那就是核糖体
That’s ribosomes.
科学家比对基因序列
Scientists line up the gene sequences
核糖体的序列去确定哪一个关系更近
of ribosomes to determine who ’ s most closely related
更近
to whom.
病毒没有核糖体
Since viruses don ’ t have ribosomes,
那就意味着没法把它们排进去
that means there ’ s no way to fit them into that paradigm.
病毒没法认定为生命
Viruses have historically just not been considered enough to count as life.
它不够复杂 没有足够强大的基因组
Not enough complexity, not a big enough genome to fit
在我们已有的认知里
in the same camp as life as we know it.
但谈论继续
But there’s still a debate going on. Like,
或许我们都成了细胞沙文主义
maybe we’re being cell chauvinists.
毕竟 病毒没有核糖体
After all, viruses don ’ t have ribosomes,
细胞生物也没有衣壳蛋白质
but we cellular organisms don ’ t have capsid proteins,
它构成了许多病毒的外壳
which form the coats of many viruses.
巨病毒让讨论发酵
And giant viruses are supercharging that debate
因为它更复杂
because they are more complex and they do
而且有大量的碱基对
have big genomes.
更不用说
Not to mention,
它们有蛋白质制造机制
they have some of that protein-making machinery that was thought to be unique to
这一机制使得我们成为蛋白质构成细胞生物
us proper protein-making cellular creatures.
关于噬病毒体的发现引起很大的关注
And the discovery of virophages has firedthings up, too.
噬病毒体的DNA能够转录成其宿主的DNA
Virophage DNA can become integrated into the DNA
像其它病毒一样
of its host virus, just like other viral
基因可以转录给宿主
genomes can integrate into cellular hosts.
假如巨病毒能像细胞一样被捕食
So if giant viruses can be preyed on like cells…
或许要讨论一下
maybe that ’ s an argument that we
应该认为它更具活性
should think of them as being more alive.
至少 据科学家说
At least, according to some scientists.
目前 我们只发现了18种噬病毒体
We ’ ve only discovered 18 types of virophages so far,
在各种各样的地方发现了病毒 从南极洲湖
in places as diverse as lakes in Antarctica
到法国制造的隐形眼镜液里都有
to contact lens fluid in France.
它们中的一些仅局限在基因研究
Many of those are just hits in genome searches,
只是基因序列相似
meaning sequences similar to known virophages
噬病毒体已进入基因层面研究
have turned up in genomic studies.
关于对它们的任何研究 还不够细致深入
Nothing about them has actually been studied in detail yet,
我们不知道它们的模样
so we don ’ t know what they
不知道它们感染了什么
look like or what they infect.
仅仅是发现了它们
Which only sort of counts as discovering them.
好像是还有很多
But it seems like there could be plenty more
噬病毒体还有巨病毒
of them out there, and virophages and giant
或许很普通 并不是我们想象的那样
viruses might be more common than we expect.
病毒是不是生物
The question of whether viruses are alive isn
在一个4分钟的视频里 并不是我们能回答的
’ t something we ’ re going to answer
因为它不是一件生物学家
in a 4 minute video… because it ’ s not something
很快就能
that biologists are going to settle
解决的事
any time soon.
详情我们将在另一个视频里解说
The more we try to categorize evolution in neat boxes,
它抛给我们更多的疑虑
the more curveballs it throws us.
一个病毒吃病毒的世界将揭示出来
It’s a virus-eat-virus world out there.
谢谢NordVPN对本视频的赞助
Thanks to NordVPN for sponsoring this episode.
我热爱互联网 在上面也花了不少时间
I love the internet and I spend a lot of time on it. But,
虽然我很爱它
as much as I love it,
它并不是像我期待的
the internet is not always as secure
那样可靠
as I would like it to be.
有了NORDVPN 你联网就安全了
With NordVPN, you can make your connectionto the internet safer.
你个人发送的一切
Everything you send over a private,
密码保护 联网等操作都被加密
password-protected internet connection is encrypted, which keeps
保证安全
it safe from snoopers.
你正在观看的是《科学秀》
But say you ’ re watching a SciShow video
假如在咖啡馆里观看 这可是一个不安全的上网场所
in a coffee shop—so, on a public unsecured
有了它 就不用愁
network—that’s great!
我能推荐这个视频吗?
May I recommend this episode on caffeine?
原来是
The thing is,
任何人都能在公共平台看到你正在干嘛
anyone can see what you ’ re doing on a public network.
这就是为什么站点有敏感信息
This is why websites that involve sensitive information,
就像你的账户 在全球资源定位器里有安全超文本传输协议
like your bank, have H-T-T-P-S
这就意味着你在网站所做的一切都有加密
in the URL which means everything you do on that site is encrypted.
即使站点使用安全超文本传输协议 还是很容易被攻击
But even sites that use https can be vulnerable to more sophisticated attacks.
有了VPN 你所有的数据在传输之前被加密
With a VPN (or Virtual Private Network) allof your data gets encrypted before it ever
在传到一个网站之前 在一个可信赖的服务器里
leaves your computer, then re-routed through a trusted server
传输
before it ’ s sent onto the site.
另一个方向
In the other direction,
传给你的数据之前也经过服务器的
data sent to you by the other side is encrypted by the server
加密
before it gets to you.
你的个人信息绝对安全 有点复杂
So your personal information is totally safe sounds complicated,
但NORDVPN会做好的
but NordVPN does it all
我们有4400个高速服务器分布在62个国家
for you with over 4400 super fast servers in 62 countries,
还有新成员加入
and they ’ re adding new
全程保障服务
secure servers all the time.
当你在安卓手机上检查你的信息
And whether you check your private information on your Android phone,
在平板 或者电子书上
or iPad, or your ChromeBook,
NORDVPN将在多操作系统之间工作
NordVPN will work across different operating systems and
一个计划可以用在六个
one plan can be used on up to
设备上
6 devices.
用《科学秀》代码 和NORDVPN签约
Use the code “SCISHOW” and sign up atNordVPN.
3年内 77折扣
com/SciShow to get 77% off a 3-year
VPN计划
VPN plan.
#音乐#
[♪OUTRO]

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视频概述

病毒和细菌不同

听录译者

收集自网络

翻译译者

Tiger_woo

审核员

审核员YX

视频来源

https://www.youtube.com/watch?v=GxCo5PcVAOc

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