ADM-201 dump PMP dumps pdf SSCP exam materials CBAP exam sample questions

表观遗传学:为什么遗传比我们想象的还要诡异 – 译学馆
未登录,请登录后再发表信息
最新评论 (0)
播放视频

表观遗传学:为什么遗传比我们想象的还要诡异

Epigenetics: Why Inheritance Is Weirder Than We Thought

一般情况下 水果的香味并不会让老鼠逃跑
The sweet smell of fruit doesn’t normally send rats running.
但是当研究者让老鼠闻到混有橘子 樱桃 扁桃味道的化学物苯乙酮时
But when researchers paired the orange-cherry-almondy scent of the chemical acetophenone with a
同时施以电击 实验鼠很快便学会了害怕
painful electric shock, lab rats quickly learned to fear it.
同时 它们的鼻腔内产生更多的神经元细胞
Along the way, extra neurons sprouted in their noses and in the smell-processing center of
大脑的嗅觉神经中枢能增加气味的敏感度
their brains, making them super-sensitive to the scent.
这个结果并不令人震惊
This result isn’t shocking.
令人震惊的是这些老鼠的子嗣 以及子嗣的子嗣
What is surprising is that the rats’ pups – and their pups’ pups – were also startled
同样对苯乙酮的气味感到害怕 并且拥有同父辈一样额外的神经元细胞
by the smell of acetophenone and had the same extra neurons as their fathers, despite never
但父辈并没有告诉它们这种气味的可怕 它自己之前也没有闻过
having been introduced to either their dads or the fruity scent before.
父辈是怎样把这种认知遗传给下一代呢?
But how could the pups have inherited something their fathers learned?
经典遗传学告诉我们只有DNA可以遗传给下一代
Basic genetics tells us that only DNA gets passed along to offspring; characteristics
而记忆 疤痕或者强健的肌肉等特征则不能
like memories, scars, or giant muscles, can’t get passed on since acquiring them doesn’t
因为这些不能改变遗传密码
alter the genetic code.
结果表明 灌输给老鼠的恐惧逐渐引发了遗传的改变
But it turns out that instilling fear in the rats did trigger genetic changes – not in
这不是由于DNA序列本身引起的
the DNA sequence itself, but instead, in how that code was read and used in the rats’
而取决于读取和利用基因的方式
bodies.
在每个细胞中 DNA不断被不断转译成蛋白质的机制
In every cell, biological machinery constantly translates DNA into the proteins needed to
是非常重要的生物学过程
carry out vital processes.
附着在DNA上的化学开关能关闭或开启对应的基因
Chemical switches attached to the DNA turn genes on and off or up and down, telling the
控制蛋白质的产生及产量
machinery which proteins to produce and in what quantities.
这些开关 被称为“表观遗传标记”这就是为什么就算有相同的DNA
These switches, called “epigenetic tags,” are why a kidney cell looks and acts differently
肾细胞的外观和功能都不同于皮肤细胞 神经元细胞
than a skin or nerve cell, even though the two cells’ DNA is identical.
这些开关在细胞中并非一成不变:它们使老鼠嗅觉基因过度表达
But the switches in any one cell aren’t set in stone: teaching those rats to fear
从而使得其对水果的味道感到害怕
that fruity smell switched one of their smell-sensing gene into overdrive.
研究者不知道这个开关在老鼠身体的哪个部位起作用
Researchers don’t know all the places in the rats’ bodies where this switch got flipped,
但是有一类重要细胞中必然存在:即老鼠的精子细胞
but they know it happened in one key set of cells: the rats’ sperm cells, which would
某天会携带这种改变过的基因
one day pass along this tweaked genetic material, making the next generation of rats super-sensitive
使其对乙酰苯过敏
to acetophenone.
啮齿类动物不是唯一有过这种神奇的遗传现象的动物
Rodents aren’t the only creatures demonstrating this weird type of inheritance.
在瑞典的奥涡卡利克斯 饱经冬日饥寒的健康男子
In Överkalix, Sweden, boys who suffered through tough winter famines went onto have super-healthy
其子代身体健康 得心脏疾病或者糖尿病的风险极低
sons, with extremely low risks of heart disease and diabetes.
而其孙子辈同样身体非常健康 难以置信的是
And their sons’ sons had the same excellent health, living an unbelievable 32 years longer,
相比那些不挨饿的人 他们的孙子辈平均多活32年
on average, than the grandsons of boys who hadn’t gone hungry.
明确的说 这并不代表我们为了下下一代的利益
To be clear, this does not mean we should start starving our kids for the benefit of
要让我们的孩子挨饿-科学家们至今也还没有完全弄清
future generations – scientists don’t even know yet exactly which switches the Swedish
是哪种开关维持了瑞典人的健康
famines flipped.
虽然我们已经弄清表观遗传的改变对老鼠健康的影响
While we have been able to connect specific epigenetic changes to health effects in mice,
但是对于人类的表观遗传学研究还有很长的路要走
we’re a long way off from being able to make those connections in humans.
听上去很令人失望 但这大部分是因为我们人类的活动不能被很好的操控
That may sound like a bummer, but it’s mostly because we humans don’t live in the well-controlled
毕竟我们不是实验室的小白鼠
environment of a laboratory.
所以 我们要懂得满足
And for that, we should be grateful.
支持《分钟地球》网址

发表评论

译制信息
视频概述

有关表观遗传学的一些小知识

听录译者

收集自网络

翻译译者

CandyV

审核员

审核团MG

视频来源

https://www.youtube.com/watch?v=AvB0q3mg4sQ

相关推荐