The wonders of the molecular world, animated | Janet Iwasa

翻译人员: Wanting Zhong 校对人员: Yolanda Zhang

I live in Utah,

我在犹他州生活，

a place known for having some of the most awe-inspiring

这里因拥有地球上最令人惊叹 的一些自然景观

natural landscapes on this planet.

而闻名遐迩。

It's easy to be overwhelmed by these amazing views,

这些壮丽的景观 是那么震撼心魄，

and to be really fascinated by these sometimes alien-looking formations.

这些时常犹如世外之物 的形态也令人深深着迷。

As a scientist, I love observing the natural world.

作为一名科学家， 我热爱观察自然世界。

But as a cell biologist,

但作为一名细胞生物学家，

I'm much more interested in understanding the natural world

我更感兴趣的是 在一个更加微小的尺度上

at a much, much smaller scale.

理解自然世界。

I'm a molecular animator, and I work with other researchers

我是一名分子动画师， 我与其他研究者合作，

to create visualizations of molecules that are so small,

为小到看不见的分子

they're essentially invisible.

创作可视化影像。

These molecules are smaller than the wavelength of light,

这些分子比光的波长还小，

which means that we can never see them directly,

也就是说，我们永远不可能 直接看见它们，

even with the best light microscopes.

即使用最先进的 光学显微镜也做不到。

So how do I create visualizations of things

那么我是如何为 小到看不见的东西

that are so small we can't see them?

创作视觉图像的呢？

Scientists, like my collaborators,

科学家们，例如我的合作伙伴，

can spend their entire professional careers

往往会终其职业生涯

working to understand one molecular process.

致力于理解一个分子过程。

To do this, they carry out a series of experiments

为此，他们进行了一系列实验，

that each can tell us a small piece of the puzzle.

每个实验能告诉我们 这块拼图的一小部分。

One kind of experiment can tell us about the protein shape,

一种实验能告诉我们 蛋白质的形状，

while another can tell us

另一种实验则能告诉我们

about what other proteins it might interact with,

这个分子会和其他 哪些蛋白互动，

and another can tell us about where it can be found in a cell.

更有别的实验告诉我们 它在细胞里的什么地方。

And all of these bits of information can be used to come up with a hypothesis,

所有这些信息的碎片整合在一起， 就能形成一个假设，

a story, essentially, of how a molecule might work.

也就是一个关于分子 如何工作的故事。

My job is to take these ideas and turn them into an animation.

我的工作就是把这些概念 转换成动画。

This can be tricky,

这个工作可以很棘手，

因为事实上，分子的行为很难琢磨。

because it turns out that molecules can do some pretty crazy things.

But these animations can be incredibly useful for researchers

但这些动画对研究者相当有用，

to communicate their ideas of how these molecules work.

可以帮助他们沟通关于 分子工作原理的想法，

They can also allow us to see the molecular world

也能让我们通过它们的眼睛

through their eyes.

看见分子世界。

I'd like to show you some animations,

我想展示一些动画，

a brief tour of what I consider to be some of the natural wonders

带领大家进行一场短途观光， 看看我心目中

of the molecular world.

分子世界的“自然奇观”。

First off, this is an immune cell.

第一个是免疫细胞。

These kinds of cells need to go crawling around in our bodies

这些细胞在我们身体里四处爬行，

in order to find invaders like pathogenic bacteria.

以便发现诸如病菌 这样的入侵者。

This movement is powered by one of my favorite proteins

它的动作由我 最喜欢的蛋白之一，

called actin,

肌动蛋白驱动，

which is part of what's known as the cytoskeleton.

这种蛋白是所谓 “细胞骨架”的一部分。

Unlike our skeletons,

和我们的骨架不同，

actin filaments are constantly being built and taken apart.

肌动蛋白纤维（微丝） 一直在不停的被组装和拆散。

The actin cytoskeleton plays incredibly important roles in our cells.

肌动蛋白骨架在我们的细胞中 扮演着至关重要的角色。

They allow them to change shape,

它们让细胞改变形状，

to move around, to adhere to surfaces

四处移动，附着于表面，

and also to gobble up bacteria.

以及吞噬细菌。

Actin is also involved in a different kind of movement.

肌动蛋白还和另一种 不同的运动有关。

In our muscle cells, actin structures form these regular filaments

在我们的肌肉细胞中， 肌动蛋白结构形成了这些

that look kind of like fabric.

看起来像布料的规则纤维。

When our muscles contract, these filaments are pulled together

当肌肉收缩时， 这些纤维就收紧，

and they go back to their original position

当肌肉放松时，

它们又恢复到原来的位置。

when our muscles relax.

Other parts of the cytoskeleton, in this case microtubules,

细胞骨架的其它组成部分， 比如说微管，

are responsible for long-range transportation.

则负责长途运输。

They can be thought of as basically cellular highways

你可以把它们想象成 细胞的高速公路，

that are used to move things from one side of the cell to the other.

用来把东西从细胞一端 运送到另一端。

Unlike our roads, microtubules grow and shrink,

和我们的公路不同， 微管能够生长、收缩，

appearing when they're needed

在需要它们时出现，

and disappearing when their job is done.

完成任务后消失。

The molecular version of semitrucks

半挂式卡车的分子版本

are proteins aptly named motor proteins,

则被贴切的称为“马达蛋白”，

that can walk along microtubules,

它们能在微管上行走，

dragging sometimes huge cargoes,

有时候在身后拖着大型“货物”，

like organelles, behind them.

比如说细胞器。

This particular motor protein is known as dynein,

这种马达蛋白叫做动力蛋白，

and its known to be able to work together in groups

能够以小组为单位工作，

that almost look, at least to me, like a chariot of horses.

至少在我看来， 几乎和战车的马匹一样。

As you see, the cell is this incredibly changing, dynamic place,

如各位所见，细胞是一个 时刻变化、非常活跃的地方，

where things are constantly being built and disassembled.

各种东西都在不停的 被修筑和拆解。

But some of these structures

但其中有些结构

are harder to take apart than others, though.

却比别的更难拆散，

必须动用特殊的力量

And special forces need to be brought in

以确保这些结构能被及时拆除。

in order to make sure that structures are taken apart in a timely manner.

That job is done in part by proteins like these.

这份工作的一部分 是由这些蛋白胜任的。

These donut-shaped proteins,

这些甜甜圈形状的蛋白

of which there are many types in the cell,

种类繁多，分布在细胞各处，

all seem to act to rip apart structures

看上去全都能将单个蛋白 拖进中央孔洞，

从而把蛋白结构撕扯开来。

by basically pulling individual proteins through a central hole.

When these kinds of proteins don't work properly,

当这种蛋白无法正常工作时，

the types of proteins that are supposed to get taken apart

本应被它们分解的那些蛋白

can sometimes stick together and aggregate

有时会黏在一起，聚集成块，

and that can give rise to terrible diseases, such as Alzheimer's.

这有可能引起可怕的疾病， 比如阿茨海默症。

And now let's take a look at the nucleus,

现在让我们看看细胞核，

which houses our genome in the form of DNA.

其内部以 DNA 的形式 保管着我们的基因组。

In all of our cells,

在我们所有的细胞中，

our DNA is cared for and maintained by a diverse set of proteins.

DNA 由一组功能各异 的蛋白照料和维护。

DNA is wound around proteins called histones,

DNA 被缠绕在组蛋白上，

which enable cells to pack large amounts of DNA into our nucleus.

这样细胞就能把大量 DNA 塞进细胞核里。

These machines are called chromatin remodelers,

这些“机器”被称为染色质重塑器，

and the way they work is that they basically scoot the DNA

它们载着 DNA

around these histones

在组蛋白上移动，

and they allow new pieces of DNA to become exposed.

让新的 DNA 片段暴露出来。

This DNA can then be recognized by other machinery.

这段 DNA 随后能被 其它“机器”所识别。

In this case, this large molecular machine

在这个例子中， 这个大型分子机器

is looking for a segment of DNA

在寻找一段能告诉它

that tells it it's at the beginning of a gene.

“这里是基因的起始位置” 的 DNA。

Once it finds a segment,

当它找到这个片段后，

it basically undergoes a series of shape changes

它会进行一系列形状变化，

which enables it to bring in other machinery

以结合其他的“装置”，

that in turn allows a gene to get turned on or transcribed.

最终启动或转录基因。

This has to be a very tightly regulated process,

这个过程必须被非常严密的控制，

because turning on the wrong gene at the wrong time

因为在错误的时间 启动错误的基因

can have disastrous consequences.

将导致灾难性后果。

Scientists are now able to use protein machines

科学家们现在能够 利用蛋白机器

to edit genomes.

编辑基因组。

I'm sure all of you have heard of CRISPR.

我相信大家都听说过 CRISPR。 [ 注：一种基因编辑技术]

CRISPR takes advantage of a protein known as Cas9,

CRISPR 技术利用一种 叫做 Cas9 的蛋白，

which can be engineered to recognize and cut

经过工程改造后， Cas9 能识别并剪切

a very specific sequence of DNA.

DNA 上非常特定的序列。

In this example,

在这个例子里，

two Cas9 proteins are being used to excise a problematic piece of DNA.

我们用两个 Cas9 蛋白 切除了一段有问题的 DNA，

For example, a part of a gene that may give rise to a disease.

比如说，基因中一个 可能引起疾病的片段，

Cellular machinery is then used

然后利用细胞机器

to basically glue two ends of the DNA back together.

把 DNA 的两个断点 重新“黏合”起来。

As a molecular animator,

作为一名分子动画师，

one of my biggest challenges is visualizing uncertainty.

我面临的最大挑战之一 就是如何将不确定性具象化。

All of the animations I've shown to you represent hypotheses,

我给各位展示的所有动画 代表的只是一些假设，

是我的合作者们基于 他们掌握的最佳信息，

how my collaborators think a process works,

based on the best information that they have.

对于一个分子过程的设想。

But for a lot of molecular processes,

但对于很多分子过程来说，

we're still really at the early stages of understanding things,

我们对它们的理解 仍处于初始阶段，

and there's a lot to learn.

还有许多待研究之处。

The truth is

事实是，

that these invisible molecular worlds are vast and largely unexplored.

这些看不见的分子世界 幅员辽阔，大部分还未经勘探。

To me, these molecular landscapes

对我来说，这些分子景观

are just as exciting to explore as a natural world

和我们身边看得见 的自然世界一样，

that's visible all around us.

是那么引人入胜。

Thank you.

谢谢。

(Applause)

（掌声）