Cheryl Hayashi: The magnificence of spider silk

譯者: Joan Liu 審譯者: Bill Hsiung

I'm here to spread the word about the

我為了宣傳蜘蛛的偉大

magnificence of spiders

及眾多可向其學習之處

and how much we can learn from them.

而來到這邊。

Spiders are truly global citizens.

蜘蛛是世界公民，

You can find spiders in nearly

你幾乎可以在世界各地

every terrestrial habitat.

皆發現到蜘蛛的蹤跡。

This red dot marks

這些紅點

the Great Basin of North America,

是北美大盆地，

and I'm involved with an alpine biodiversity

我與一些人在那邊合作

project there with some collaborators.

研究高山生物多樣性。

Here's one of our field sites,

這是一個我們做田野調查的地方，

and just to give you a sense of perspective,

讓你們瞭解一下，

this little blue smudge here,

這些藍色的點點，

that's one of my collaborators.

那是我合作的其中一個對象。

This is a rugged and barren landscape,

這是一個崎嶇的荒蕪地，

yet there are quite a few spiders here.

但那裡也有許多蜘蛛。

Turning rocks over revealed this crab spider

把石頭翻開就會發現下面有很多蟹蛛

grappling with a beetle.

抓著甲蟲。

Spiders are not just everywhere,

蜘蛛不只是到處都是，

but they're extremely diverse.

它們也極其多樣化。

There are over 40,000 described species

已知的蜘蛛種類有

of spiders.

四萬多種。

To put that number into perspective,

為了讓你們對此數字有更深刻的體認，

here's a graph comparing the 40,000

這個圖將四萬種蜘蛛

species of spiders

和四百種靈長類

to the 400 species of primates.

放在一起做比較。

There are two orders of magnitude more

蜘蛛比靈長類

spiders than primates.

多了百倍。

Spiders are also extremely old.

蜘蛛也是很古老的。

On the bottom here,

在這邊底下，

this is the geologic timescale,

這是地質時間表，

and the numbers on it indicate millions

這些數字代表百萬年前，

of years from the present, so the zero here,

所以這邊這個零

that would be today.

就是現在。

So what this figure shows is that spiders

這個圖表告訴我們

date back to almost 380 million years.

蜘蛛在三億八千多萬年前就存在了。

To put that into perspective, this red

巨觀來看，這個紅線

vertical bar here marks the divergence time

劃出人和黑猩猩

of humans from chimpanzees,

開始分歧的時間點，

a mere seven million years ago.

僅僅發生在七百萬年前。

All spiders make silk

所有蜘蛛在它一生中

at some point in their life.

的某些時刻都會製造蜘蛛絲。

Most spiders use copious amounts of silk,

大部份蜘蛛會用大量的蜘蛛絲，

and silk is essential to their survival

且蜘蛛絲對牠們的生存

and reproduction.

和繁殖非常重要。

Even fossil spiders can make silk,

就連遠古時期的蜘蛛也可以製造絲，

as we can see from this impression of

我們可以從這個化石印記上

a spinneret on this fossil spider.

看到這石化蜘蛛的噴絲頭。

So this means that both spiders

所以這表示

and spider silk have been around

蜘蛛和蜘蛛絲都已存在

for 380 million years.

三億八千多萬年了。

It doesn't take long from working with spiders

其實不需要研究蜘蛛很久

to start noticing how essential silk is

就可以發現蜘蛛絲對蜘蛛有多重要

to just about every aspect of their life.

幾乎與蜘蛛生存的每一個層面都息息相關。

Spiders use silk for many purposes, including

蜘蛛用蜘蛛絲做很多事，

the trailing safety dragline,

像是用以作攀登的安全索、

wrapping eggs for reproduction,

包覆卵以利繁殖、

protective retreats

協助逃跑、

and catching prey.

和捕捉獵物。

There are many kinds of spider silk.

蜘蛛絲有很多種，

For example, this garden spider can make

舉例來說，這種花園蜘蛛

seven different kinds of silks.

可以製造七種蜘蛛絲。

When you look at this orb web, you're actually

當你看著這個蜘蛛網的時候，

seeing many types of silk fibers.

你事實上正在看著很多種絲纖維。

The frame and radii of this web

網的外框與輻射狀軸線

is made up of one type of silk,

是由一種蜘蛛絲構成的，

while the capture spiral is a composite

而這用來捕捉獵物的螺旋狀絲線，

of two different silks:

是由兩種不同的絲所組成的：

the filament and the sticky droplet.

分別是絲狀物和這黏稠的液滴。

How does an individual spider

一隻蜘蛛是如何

make so many kinds of silk?

製造這麼多種的蜘蛛絲呢？

To answer that, you have to look a lot closer

要回答這個問題，你們必須更仔細地觀察

at the spinneret region of a spider.

蜘蛛的噴絲頭區域。

So silk comes out of the spinnerets, and for

蜘蛛從噴絲頭吐出絲，

those of us spider silk biologists, this is what

而對我們這些研究蜘蛛絲的生物學家來說，

we call the "business end" of the spider. (Laughter)

我們稱這個地方為蜘蛛「辦公」的地方。（笑聲）

We spend long days ...

我們花很多時間

Hey! Don't laugh. That's my life.

嘿！不要笑！這是我的人生。

(Laughter)

（笑聲）

We spend long days and nights

我們日以繼夜地盯著

staring at this part of the spider.

蜘蛛的這個部份。

And this is what we see.

而這是我們所看到的。

You can see multiple fibers

你們可以看到數條絲纖維

coming out of the spinnerets, because

從噴絲頭出來，

each spinneret has many spigots on it.

因為每一個噴頭都有許多噴嘴。

Each of these silk fibers exits from the spigot,

每一條絲纖維從其中的一個噴嘴噴出，

and if you were to trace the fiber back

而如果你順著纖維回溯到蜘蛛體內，

into the spider, what you would find is that

你會發現

each spigot connects to its own individual

每一個噴頭都連接著一個獨有的絲腺。

silk gland. A silk gland kind of looks like a sac

絲腺看起來像是一個

with a lot of silk proteins stuck inside.

含有很多絲蛋白的囊袋。

So if you ever have the opportunity to dissect

所以如果你有機會解剖

an orb-web-weaving spider,

圓網蜘蛛的話，

and I hope you do,

我希望你真的有這樣的機會，

what you would find is a bounty

你會看到很多

of beautiful, translucent silk glands.

很漂亮的透明絲腺。

Inside each spider, there are hundreds

每一隻蜘蛛有幾百

of silk glands, sometimes thousands.

到幾千個絲腺。

These can be grouped into seven categories.

這些腺體可以被分為七大類，

They differ by size, shape,

它們在大小、形狀、

and sometimes even color.

有時甚至顏色上皆不同。

In an orb-web-weaving spider,

一隻圓網蜘蛛身上

you can find seven types of silk glands,

可以找到七種不同的絲腺，

and what I have depicted here in this picture,

而我在這張圖片中所標示出來的，

let's start at the one o'clock position,

從一點鐘方向開始，

there's tubuliform silk glands, which are used

這是管狀絲腺，是用來

to make the outer silk of an egg sac.

製造蛋囊外面的絲。

There's the aggregate and flagelliform silk

這裡有聚結和條狀絲腺，

glands which combine to make the sticky

這兩種絲腺合起來可以製造

capture spiral of an orb web.

圓網中的黏性捕捉螺旋絲。

Pyriform silk glands make the attachment

梨狀絲腺製造接著膠水，

cement -- that's the silk that's used to adhere

就是用來將絲線和基質

silk lines to a substrate.

黏接在一起的絲。

There's also aciniform silk,

還有用來包覆獵物的

which is used to wrap prey.

葡萄絲。

Minor ampullate silk is used in web construction.

小型壺狀絲被用來製造蜘蛛網。

And the most studied silk line

而最常被研究的蜘蛛絲

of them all: major ampullate silk.

就是大型壺狀絲。

This is the silk that's used to make the frame

這是被用來製造圓型蜘蛛網

and radii of an orb web, and also

的外框和半徑的絲，也被用作

the safety trailing dragline.

安全防護索使用。

But what, exactly, is spider silk?

但蜘蛛絲到底是什麼呢？

Spider silk is almost entirely protein.

蜘蛛絲幾乎全由蛋白質所組成。

Nearly all of these proteins can be explained

大部分的這些蛋白

by a single gene family,

可以經由一個基因家族來解釋，

so this means that the diversity of silk types

也就是說我們看到的這麼多種蜘蛛絲

we see today is encoded by one gene family,

都是由一個基因家族所編碼出來的。

so presumably the original spider ancestor

所以很有可能蜘蛛的祖宗

made one kind of silk,

只製造一種絲，

and over the last 380 million years,

而且在這三億八千萬年之中，

that one silk gene has duplicated

那個絲基因複製、

and then diverged, specialized,

分歧、特化

over and over and over again, to get

一次又一次，

the large variety of flavors of spider silks

直到現在有這麼多種

that we have today.

不同的蜘蛛絲。

There are several features that all these silks

這麼多種不同的蜘蛛絲有數個共通點，

have in common. They all have a common

它們都有非常相似的設計，

design, such as they're all very long --

像是它們都非常長，

they're sort of outlandishly long

也就是說它們比一般的蛋白質

compared to other proteins.

長很多很多。

They're very repetitive, and they're very rich

它們重複性很高，且它們含有大量的

in the amino acids glycine and alanine.

甘胺酸和丙胺酸。

To give you an idea of what

為了讓你們有個概念，

a spider silk protein looks like,

蜘蛛絲蛋白看起來大概像是這樣，

this is a dragline silk protein,

這是牽引絲蛋白，

it's just a portion of it,

這只是黑寡婦蜘蛛

from the black widow spider.

的蜘蛛絲蛋白的一部份。

This is the kind of sequence that I love

這是我最愛的一種序列，

looking at day and night. (Laughter)

我可以日以繼夜地看他。（笑聲）

So what you're seeing here is the one letter

所以你們現在看到的這些是

abbreviation for amino acids, and I've colored

胺基酸的單字母縮寫，

in the glycines with green,

我把甘胺酸標記成綠色，

and the alanines in red, and so

然後把丙胺酸標記成紅色。

you can see it's just a lot of G's and A's.

所以你可以看到有很多的 G 和 A。

You can also see that there's a lot of short

你也可以看到有許多的短序列

sequence motifs that repeat over and over

一再地重複又重複，

and over again, so for example there's a lot of

舉例來說這邊有很多我們叫作

what we call polyalanines, or iterated A's,

聚合丙胺酸的片段，也就是很多個 A。

AAAAA. There's GGQ. There's GGY.

這是 GGQ，這是 GGY。

You can think of these short motifs

你們可以把這些

that repeat over and over again as words,

不斷重複的短序列當成文字，

and these words occur in sentences.

而這些文字在句子裡面出現。

So for example this would be one sentence,

舉例來說這是一個句子，

and you would get this sort of green region

然後你有這些綠色的部份

and the red polyalanine, that repeats

和這些紅色的聚丙胺酸會一直

over and over and over again,

不斷地不斷地重複，

and you can have that hundreds and

而且你可以在單一個絲分子中

hundreds and hundreds of times within

找到好幾百次

an individual silk molecule.

的重複。

Silks made by the same spider can have

由同一隻蜘蛛所製造的絲可以有

dramatically different repeat sequences.

非常不同的重複序列。

At the top of the screen, you're seeing

在螢幕上方，你可以看到

the repeat unit from the dragline silk

金蛛牽引絲的

of a garden argiope spider.

重複單元，

It's short. And on the bottom,

它很短。在下面，

this is the repeat sequence for the

這是同一種蜘蛛

egg case, or tubuliform silk protein,

蛋殻的重複序列，

for the exact same spider. And you can see

也就是管狀絲蛋白。你們可以看出

how dramatically different

這兩種絲蛋白

these silk proteins are -- so this is

有多麼不同 — 這就是

sort of the beauty of the diversification

蜘蛛絲基因家族分歧

of the spider silk gene family.

漂亮的地方。

You can see that the repeat units differ

你可以看到這些重複序列的

in length. They also differ in sequence.

長短不同，它們的序列也不同。

So I've colored in the glycines again

所以這裡我再把甘胺酸標記成綠色、

in green, alanine in red, and the serines,

丙胺酸為紅色、絲氨酸

the letter S, in purple. And you can see

縮寫為 S，標記成紫色。你可以看到

that the top repeat unit can be explained

這些在上方的重複序列

almost entirely by green and red,

幾乎全是綠色和紅色，

and the bottom repeat unit has

在這下面的重複序列

a substantial amount of purple.

有很多紫色。

What silk biologists do is we try to relate

絲生物學家想將

these sequences, these amino acid

這些胺基酸的序列

sequences, to the mechanical properties

與絲纖維的機械性質

of the silk fibers.

連結起來。

Now, it's really convenient that spiders use their silk

蜘蛛僅在體外使用它們的蜘蛛絲

completely outside their body.

對我們來說是非常便利的。

This makes testing spider silk really, really

這讓在實驗室中研究蜘蛛絲

easy to do in the laboratory, because

非常、非常容易，

we're actually, you know, testing it in air

因為我們實際上是在空氣中測試它，

that's exactly the environment that

而這也正是

spiders are using their silk proteins.

蜘蛛使用牠們絲蛋白的環境。

So this makes quantifying silk properties by

所以這些特性

methods such as tensile testing, which is

讓我們可以做拉伸測試，

basically, you know, tugging on one end

也就是

of the fiber, very amenable.

在纖維兩側拉扯。

Here are stress-strain curves

這是從同一隻蜘蛛的

generated by tensile testing

五種蜘蛛絲的

five fibers made by the same spider.

拉伸測試所得到的受力圖。

So what you can see here is that

你們可以看到

the five fibers have different behaviors.

這五種絲各有不同的表現。

Specifically, if you look on the vertical axis,

如果你看 y 軸，這是拉力。

that's stress. If you look at the maximum

如果你看每一種絲

stress value for each of these fibers,

可以承受的拉力，

you can see that there's a lot of variation,

你會看到有很大的變異。

and in fact dragline, or major ampullate silk,

牽引絲，也就是大型壺狀絲，

is the strongest of these fibers.

是最強壯的絲。

We think that's because the dragline silk,

我們認為這是因為牽引絲

which is used to make the frame and radii

是用來製作蜘蛛網外框和半徑的材料，

for a web, needs to be very strong.

它需要非常強壯。

On the other hand, if you were to look at

從另一個角度看，如果你觀察應力，

strain -- this is how much a fiber can be

這是纖維可以延伸的程度，

extended -- if you look at the maximum value

如果你看在這邊這個最大值，

here, again, there's a lot of variation

又一次地，也是有很大的變異，

and the clear winner is flagelliform,

很明顯的這次是條狀絲

or the capture spiral filament.

或稱捕捉螺旋絲大勝。

In fact, this flagelliform fiber can

事實上，條狀纖維

actually stretch over twice its original length.

可以延伸到超過原來長度的兩倍。

So silk fibers vary in their strength

也就是說絲纖維的強度

and also their extensibility.

和延展性都不相同。

In the case of the capture spiral,

以捕捉螺旋絲來說，

it needs to be so stretchy to absorb

它需要有很好的延展性

the impact of flying prey.

來吸收獵物落網的衝力。

If it wasn't able to stretch so much, then

如果它們沒有這麼好的延展性，

basically when an insect hit the web,

當有昆蟲落入蜘蛛網的時候，

it would just trampoline right off of it.

昆蟲只會直接從蜘蛛網上彈下來。

So if the web was made entirely out of

所以如果整張網都是由牽引絲所組成，

dragline silk, an insect is very likely to just

那麼昆蟲只會直接

bounce right off. But by having really, really

彈下來。但因為有這樣

stretchy capture spiral silk, the web is actually

延展性非常好的捕捉螺旋絲，整張網

able to absorb the impact

可以吸收獵物的衝力

of that intercepted prey.

並捕捉獵物。

There's quite a bit of variation within

一隻蜘蛛可以製造的不同絲纖維間

the fibers that an individual spider can make.

有很多差異。

We call that the tool kit of a spider.

我們稱之為蜘蛛的工具箱。

That's what the spider has

那是蜘蛛用來與環境

to interact with their environment.

互動的工具。

But how about variation among spider

但是不同種類蜘蛛間的差異呢？

species, so looking at one type of silk

如果我們觀察一種絲，

and looking at different species of spiders?

然後比較不同種類蜘蛛間這種絲的異同？

This is an area that's largely unexplored

這是一個尚未被深入研究的領域，

but here's a little bit of data I can show you.

但我可以給你們看一些數據。

This is the comparison of the toughness

這是 21 種蜘蛛間

of the dragline spilk spun

牽引絲韌度

by 21 species of spiders.

的比較。

Some of them are orb-weaving spiders and

這裡有些是圓網蜘蛛

some of them are non-orb-weaving spiders.

有些是非圓網蜘蛛。

It's been hypothesized that

一般推測這些圓網蜘蛛，

orb-weaving spiders, like this argiope here,

像是這隻金蛛，

should have the toughest dragline silks

應該有最強韌的牽引絲，

because they must intercept flying prey.

因為他們需要攔截飛行獵物。

What you see here on this toughness graph

在這張韌性表中

is the higher the black dot is on the graph,

黑點越高

the higher the toughness.

表示韌性越高。

The 21 species are indicated here by this

這 21 種蜘蛛的關係在這裡

phylogeny, this evolutionary tree, that shows

用演化樹來表示出

their genetic relationships, and I've colored

它們之間的基因關係，

in yellow the orb-web-weaving spiders.

圓網蜘蛛在這邊被我以黃色標記。

If you look right here at the two red arrows,

如果你看這邊這兩個紅色箭頭，

they point to the toughness values

它們指向

for the draglines of nephila clavipes and

金蛛 (nephila clavipes) 和

araneus diadematus.

歐洲圓蛛 (araneus diadematus) 的牽引絲強度。

These are the two species of spiders

絕大多數的金錢和時間

for which the vast majority of time and money

都被投注在人工合成複製

on synthetic spider silk research has been

這兩種蜘蛛的牽引絲蛋白

to replicate their dragline silk proteins.

的研究上。

Yet, their draglines are not the toughest.

但牠們的牽引絲卻不是韌性最高的。

In fact, the toughest dragline in this survey

事實上，在這份調查中韌性最高的牽引絲

is this one right here in this white region,

是這個在白色區域中的這隻，

a non orb-web-weaving spider.

是一種非圓網蜘蛛。

This is the dragline spun by scytodes,

這是花皮蛛 (scytodes)

the spitting spider.

所製造的牽引絲。

Scytodes doesn't use a web at all

花皮蛛完全不用網來捕捉獵物。

to catch prey. Instead, scytodes

相反地，它們在獵物附近徘徊，

sort of lurks around and waits for prey

並等待獵物靠近，

to get close to it, and then immobilizes prey

然後將絲狀毒素吐在獵物身上

by spraying a silk-like venom onto that insect.

使獵物動彈不得。

Think of hunting with silly string.

就像是用繩索捕捉獵物一樣，

That's how scytodes forages.

花皮蛛就是這樣捕獵的。

We don't really know why scytodes

我們不是很瞭解為什麼

needs such a tough dragline,

花皮蛛需要如此強韌的牽引絲，

but it's unexpected results like this that make

但就是這樣出乎意料的結果

bio-prospecting so exciting and worthwhile.

讓生物研究如此有趣並有意義。

It frees us from the constraints

這讓我們不會被

of our imagination.

成見所囿。

Now I'm going to mark on

現在我想要談談

the toughness values for nylon fiber,

尼龍纖維、

bombyx -- or domesticated silkworm silk --

家蠶、羊毛、

wool, Kevlar, and carbon fibers.

克維拉和碳纖維的韌性。

And what you can see is that nearly

你們可以看到的是

all the spider draglines surpass them.

幾乎所有蜘蛛牽引絲的韌性都優於這些材質。

It's the combination of strength, extensibility

這樣的強度、延展性

and toughness that makes spider silk so

與韌性的組合使得蜘蛛絲如此特別，

special, and that has attracted the attention

這也是為什麼很多仿生學家

of biomimeticists, so people that turn

想要研究蜘蛛絲，也就是人們

to nature to try to find new solutions.

向大自然找尋解答。

And the strength, extensibility and toughness

蜘蛛絲這樣的強度、延展力和韌性

of spider silks combined with the fact that

再加上不會

silks do not elicit an immune response,

引發任何免疫反應，

have attracted a lot of interest in the use

讓蜘蛛絲可以有很多

of spider silks in biomedical applications,

生物醫學上的用途，

for example, as a component of

舉例來說：可以用來

artificial tendons, for serving as

製造人工韌帶、

guides to regrow nerves, and for

引導神經再生、或是

scaffolds for tissue growth.

做為組織生長的鷹架。

Spider silks also have a lot of potential

蜘蛛絲的防彈特性，

for their anti-ballistic capabilities.

也非常有應用潛力。

Silks could be incorporated into body

蜘蛛絲可以被置入人體、

and equipment armor that would be more

或裝備護具來製造

lightweight and flexible

比任何既有材質更輕更軟

than any armor available today.

的安全防具。

In addition to these biomimetic

除了蜘蛛絲的

applications of spider silks,

仿生用途外，

personally, I find studying spider silks

我個人認為研究蜘蛛絲

just fascinating in and of itself.

非常有趣。

I love when I'm in the laboratory,

我最喜歡我在實驗室的時候，

a new spider silk sequence comes in.

一個新的蜘蛛絲序列進來。

That's just the best. (Laughter)

真的超棒的（笑聲）

It's like the spiders are sharing

這有點像是蜘蛛在跟我分享

an ancient secret with me, and that's why

一個古早的祕密，這也是為什麼

I'm going to spend the rest of my life

我接下來的人生

studying spider silk.

都會繼續研究蜘蛛絲。

The next time you see a spider web,

下次你看到一張蜘蛛網，

please, pause and look a little closer.

拜託停下來更仔細地看看。

You'll be seeing one of the most

你會看到我們人類所知

high-performance materials known to man.

最高性能的材料之一。

To borrow from the writings

借用一隻名叫

of a spider named Charlotte,

夏綠蒂的蜘蛛所說的話：

silk is terrific.

絲真是太棒了！

Thank you. (Applause)

謝謝。（掌聲）

(Applause)

（掌聲）