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如何消灭掉最致命敌人——疟疾 – 译学馆
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How To Eradicate One Of Our Deadliest Enemies – Gene Drive & Malaria

What if you could use genetic engineering to stop humanity’s most
危险的人类捕食者 这个星球上最致命的动物——强大的蚊子
dangerous predator, the deadliest animal on the planet responsible for the death
它们使数十亿人丧失生命 蚊子传播很多疾病
of billions, the mighty mosquito. Along with other diseases it plays host to
是疟疾的主要传播者 地球上最残忍的寄生生物之一
Malaria, one of the cruelest parasites on Earth
possibly the single biggest killer of humans in history.
In 2015 alone
上亿人受感染 近五十万人死亡
hundreds of millions were infected and almost half a million people died.
一种新型技术可以帮助我们永远根除疟疾 但要做到这点我们需要
A new technology could help us eradicate Malaria forever, but to do so we need to
engineer a whole animal population.
这并不是一个假设问题 改进的蚊子已经在实验室存在
This is not a hypothetical problem, the modified mosquitoes already exist in a lab.
我们是否该应用这种技术 疟疾是不是糟糕到要冒风险使用该技术呢
Should we use the technology, and is malaria bad enough to risk it?
(Intro Music)
疟疾是由一组微生物导致的:疟原虫 它是一种很奇怪
Malaria is caused by a group of microorganisms: Plasmodia, very weird
的微生物 只由一个单细胞构成 他们是
microorganisms that consists of just a single-cell, they’re parasites that
完全依赖蚊子生存的寄生虫 疟疾通常是从昆虫咬伤而感染的
completely rely on mosquitoes. Malaria always starts with an insect bite.
在昆虫的唾液腺中 上千孢子等待着昆虫唾液渗透到
In its salivary glands, thousands of sporozoites wait until the insect penetrates your
皮肤中 入侵后他们立即前往肝脏
skin, immediately after invading you they head for the liver where they quietly
悄悄地进入大细胞 藏起来不被免疫系统发现 在这里呆一个月
enter big cells and hide from the immune system. For up to a month they stay here
以隐身模式吞噬活细胞 然后变成下一种形式:
in stealth mode consuming the cells alive and changing into their next form:
像裂体性孢子一样的小滴 他们自我繁殖产生成千上万个个体
small drop like merozoites, they multiply generating thousands of themselves and
然后从细胞中闯出来 成千个寄生虫顺着血流方向
then burst out of the cells. So thousands of parasites head into the bloodstream
寻找他们的下一波牺牲者: 红细胞 为了不被发现
to look for their next victims, Red blood cells, to stay unnoticed, they wrap
他们用自己杀死细胞的细胞膜包裹自己 想象一下
themselves in the membranes of the cells they killed. Imagine that! Killing someone
从内部杀死别人 然后用它的皮肤作伪装 实在太残忍
from the inside and then taking their skin as camouflage, brutal!
他们现在要猛烈地攻击红细胞 在红细胞内部繁殖 直到细胞破裂
They now violently attack red blood cells, multiplying inside them until they burst
然后找到更多红细胞 多次重复这个周期
then finding more red blood cells and this cycle repeats over and over.
许多死细胞散布大量的有毒废料 激活一个有力的
Pieces of dead cells spread lots of toxic waste material, which activates a powerful
免疫反应 导致类似流感症状的产生 这些症状包括
immune response causing flu-like symptoms, among the symptoms are high
高烧 出汗 浑身发冷 抽搐 头痛 伴有呕吐
fever, sweats and chills, convulsions, headaches and sometimes vomiting and
腹泻 如果疟疾打破了血液和大脑之间的屏障 会导致昏迷
diarrhea. If malaria breaches the blood-brain barrier it can cause coma,
神经的损坏 甚至死亡 然后寄生生物准备好撤离
neurological damage or death. The parasites are ready for evacuation now.
当另一个蚊子咬伤已经感染的人类后 他们的速度加快 周期
When another mosquito bites the infected human they get a ride, the cycle can
start over.
2015年 塞卡病毒迅速在全球扩散 如果感染了怀孕的妇女
In 2015, the Zika virus, which causes horrible birth defects if it
infects pregnant women, spread rapidly into new areas around the globe. It too
塞卡病毒同样以蚊子为载体 蚊子堪称人类疾病的完美载体
is carried by a mosquito. The mosquito is the perfect carrier for human diseases
他们至少存在了两亿年 数量达数万亿
they’ve been around for at least 200 million years. There are trillions of
仅一只蚊子一次就能产300个卵 实际上他们
them and a single one can lay up to 300 eggs at a time. They are practically
不可能根除 是完美的寄生虫载体 但今天我们有一种新的
impossible to eradicate and the perfect parasite taxi. But today we have a new
革命科技 可以使我们最终赢得战争
revolutionary technology, that could enable us to finally win the war
这种技术就是基因编辑技术 人类有史以来第一次使用这种工具
against them; CRISPR. For the first time in human history, we have the tools to
让整个物种发生快速的大规模的改变 把基因信息改造成
make fast, large-scale changes to entire species, changing their genetic
information as we please.
那么除了攻击隔离组的昆虫 为什么不改变
So instead of attacking isolated groups of insects, why not just change the
types that transmit diseases?
使用基因工程 科学家们
Using genetic engineering, scientists
成功地创造了一种蚊子 通过添加一种新型抗体基因
successfully created a strain of mosquitoes that are immune to the
使它们对寄生虫免疫 这种抗体专门针对
malaria parasite by adding a new antibody gene that specifically targets
疟原虫 这些蚊子永远都不会传播疟疾 但是仅仅改变基因信息
plasmodium. These mosquitoes will never spread malaria. But just changing genetic
是不够的 这种改变只有一半的后代能继承
information is not enough. The edits would only be inherited by half the
offspring because most genes have two versions inside the genome as a
所以繁殖两代后 最多只有一半的后代
fail-safe. So after just two generations, at most only half of the offspring would
携带该工程中的基因 针对达数十亿的蚊子
carry the engineered gene. In a population of billions of mosquitoes they would
hardly make a difference.
A genetic engineering method called the gene drive
solves this problem.
It forces the new gene to become dominant in the following generations
overpowering the old gene almost completely.
多亏这种改变 改造后的蚊子后代中有99.5%都
Thanks to this twist, 99.5% of all the engineered mosquitoes offspring will
携带这种抗疟疾编码 如果我们可以释放足够多的改造蚊子
carry the anti-malaria edit. If we were to release enough engineered mosquitoes
到野外中与普通的蚊子配对 抵抗疟疾的基因会
into the wild to mate with normal mosquitoes, the malaria blocking gene would spread
extremely quickly.
As the new gene becomes a permanent feature of the
mosquito population, Plasmodium would lose its home base.
科学家们希望这种改变速度很快 使疟原虫不能适应
Scientists hope that the change would be so fast that they could not adapt to it quickly enough.
Malaria could virtually disappear.
If you take into account that
每年可能有五十万儿童受感染致死 那你应该知道从开始观看这个视频到现在
maybe half a million children are killed by it every year, about five have died
已经有五个孩子死亡 一些科学家认为我们应该尽早使用这种技术
since this video started. Some scientists argue that we should use the technology
sooner, rather than later.
使用这种技术只会让蚊子收益 他们
The mosquitoes themselves would probably only profit from this, they don’t have
携带寄生虫一无所获 这可能仅仅是第一步
anything to gain from carrying parasites and this might only be the first step
Malaria might just be the beginning.
Different mosquitoes also carry Dengue
塞卡病毒 扁虱可以传播莱姆关节炎病毒 苍蝇可以传播昏睡病
fever and Zika, ticks transmit Lyme disease, flies transmit sleeping sickness
跳蚤传播瘟疫 我们可以拯救百万生命 防止极大规模人受难
fleas transmit the plague. We could save millions of lives and prevent suffering
那么 我们为什么还没做到呢
on an unbelievable scale. So, why haven’t we done this yet?
一方面 基因编辑技术
For one, CRISPR editing is
只出现了四年 所以直到最近我们也不能快速
barely four years old, so until very recently we just couldn’t do it as fast
轻松地完成该项技术 并且存在一些有根据的担忧
and easily. And there are valid concerns.
Never before have humans consciously changed the genetic code of a free-living
organism on this scale.
Once we do it,
就无法回头了 所以我们的做法必须正确 否则如果我们开始改变自然
there is no going back. So it has to be done right, because there could be
unwanted consequences if we set out to edit nature.
但对于疟疾这个特定案例来说 风险在可接受范围
In this specific case of malaria though, the risk might be acceptable
since the genetic modification doesn’t make a big change in the overall genome.
It only changes a very specific part.
现在 最坏的设想是
The worst-case scenario here, is probably
这项技术可能不起作用 也或者 寄生虫消极地适应了改变
that it might not work or that the parasite adapts in a negative way.
There is still much debate.
技术问题如同基因推动一般强大 它需要
Technology as powerful as gene drive, needs to be
花心思来考虑 但在某种程度上我们必须问问自己
handled with a lot of care but at some point we have to ask ourselves: Is it
每天都有1000个儿童死亡 不使用该技术会不会不道德
unethical to not use this technology, when every day 1,000 children die.
Humanity has to decide how to act on this in the next few years.
大众会随着这方面技术的发展 展开讨论
The public discussion is way behind the technology in this case.
What do you think?
这个视频可以制作 一部分得益于Patreon平台上观看者的贡献 如果你想要
This video was made possible in part by viewer donations on Patreon. If you want
帮助我们制作更多这样的视频 并得到可观奖励作为回报的话
to help us make more videos like this and get nice rewards in return you can
你可以在这儿做 我们非常感激 如果你想学习更多关于
do so here. We really appreciate it. If you want to learn more about the topic
基因工程这个话题的知识 我们有另外一个关于基因编辑技术和转基因作物的视频
of genetic engineering, we have another video about CRISPR and GMOs, and in case
如果你不想看关于生物知识的视频 这里有关于宇宙知识的列表
that’s too much biology for you, here’s a space playlist.