I'm here to spread the word about the magnificence of spiders and how much we can learn from them. Spiders are truly global citizens. You can find spiders in nearly every terrestrial habitat. This red dot marks the Great Basin of North America, and I'm involved with an alpine biodiversity project there with some collaborators. Here's one of our field sites, and just to give you a sense of perspective, this little blue smudge here, that's one of my collaborators. This is a rugged and barren landscape, yet there are quite a few spiders here. Turning rocks over revealed this crab spider grappling with a beetle.
Ma aflu aici sa va dezvalui maretia paianjenilor si despre cat de multe lucuri putem invata de la acestia. Paianjenii sunt cu adevarat cetateni ai intregului glob. Putem descoperi paianjeni in aproape orice habitat terestru. Punctele acestea rosii marcheaza Marele Bazin al Americii de Nord, si sunt implicata acolo intr-un proiect despre biodiversitatea alpina impreuna cu alti colaboratori. Iata unul dintre siturile noastre asta numai ca sa va dau o idee, pata asta mica si albastra, reprezinta unul dintre colaboratorii mei. Acesta este un tinut aspru si steril, cu toate astea, cativa paianjeni tot se gasesc. Cautand sub stanci am gasit acest paianjen-crab luandu-se la tranta cu un gandac.
Spiders are not just everywhere, but they're extremely diverse. There are over 40,000 described species of spiders. To put that number into perspective, here's a graph comparing the 40,000 species of spiders to the 400 species of primates. There are two orders of magnitude more spiders than primates. Spiders are also extremely old. On the bottom here, this is the geologic timescale, and the numbers on it indicate millions of years from the present, so the zero here, that would be today. So what this figure shows is that spiders date back to almost 380 million years. To put that into perspective, this red vertical bar here marks the divergence time of humans from chimpanzees, a mere seven million years ago.
Paianjenii nu numai ca exista pretutindeni, dar sunt si extrem de diversi. Exista peste 40.000 de specii de paianjeni atestate. Pentru a privi acest număr dintr-o altă perspectivă iata un grafic care compara cele 40.000 de specii de paianjeni cu cele 400 de specii de primate. Sunt de o suta de ori mai multe specii de paianjeni decat de primate. Paianjenii sunt de asemenea foarte vechi. La baza aici, avem scala erelor geologice, iar numerele de deasupra indica milioanele de ani plecand din prezent spre trecut, prin urmare acest zero reprezinta ziua de azi. Deci, ceea ce acest tabel vrea sa arate este ca paianjenii dateaza de aproape 380 de milioane de ani. Ca sa avem o imagine mai clara, aceasta bara verticala de aici arata evolutia oamenilor plecand de la cimpanzei, abia acum sapte milioane de ani.
All spiders make silk at some point in their life. Most spiders use copious amounts of silk, and silk is essential to their survival and reproduction. Even fossil spiders can make silk, as we can see from this impression of a spinneret on this fossil spider. So this means that both spiders and spider silk have been around for 380 million years. It doesn't take long from working with spiders to start noticing how essential silk is to just about every aspect of their life. Spiders use silk for many purposes, including the trailing safety dragline, wrapping eggs for reproduction, protective retreats and catching prey.
Toti paianjenii produc matase de-a lungul vietii lor. Cei mai multi dintre paianjeni utilizeaza o mare cantitate de matase, iar matasea este esentiala pentru supravietuirea acestora si pentru reproducere. Pana si un paianjen fosila putea produce matase, dupa cum se vede din amprenta organelor filiere acestui paianjen fosila. Deci asta inseamna ca atat paianjenii cat si matasea lor exista de 380 de milioane de ani incoace. Nu e nevoie sa lucrezi mult timp cu paianjenii ca sa realizezi cat de esential este firul de matase in aproape fiecare dintre aspectele vietii lor. Paianjenii utilizeaza firul in multe scopuri, acestea incluzand firul de deplasare - ca și coardă de siguranță, impachetarea coconilor pentru reproducere, costructia refugiilor de protectie si prinderea prazii.
There are many kinds of spider silk. For example, this garden spider can make seven different kinds of silks. When you look at this orb web, you're actually seeing many types of silk fibers. The frame and radii of this web is made up of one type of silk, while the capture spiral is a composite of two different silks: the filament and the sticky droplet. How does an individual spider make so many kinds of silk? To answer that, you have to look a lot closer at the spinneret region of a spider. So silk comes out of the spinnerets, and for those of us spider silk biologists, this is what we call the "business end" of the spider. (Laughter) We spend long days ... Hey! Don't laugh. That's my life. (Laughter) We spend long days and nights staring at this part of the spider. And this is what we see. You can see multiple fibers coming out of the spinnerets, because each spinneret has many spigots on it. Each of these silk fibers exits from the spigot, and if you were to trace the fiber back into the spider, what you would find is that each spigot connects to its own individual silk gland. A silk gland kind of looks like a sac with a lot of silk proteins stuck inside. So if you ever have the opportunity to dissect an orb-web-weaving spider, and I hope you do, what you would find is a bounty of beautiful, translucent silk glands.
Exista multe tipuri de matase de paianjen. De exemplu, acest paianjen de gradina poate sa produca sapte tipuri de matase diferite. Cand va uitati la aceasta panza de paianjen circulara, de fapt vedeti mai multe tipuri de fibre de matase. Scheletul si razele panzei de paianjen sunt realizate dintr-un anumit tip de matase, pe cand spiralele sunt realizate dintr-o compozitie a doua tipuri diferite de matase: filamentul si un mic strop de lipici. Cum poate un singur paianjen sa produca atat de multe tipuri de matase? Ca sa putem raspunde, trebuie sa privim mult mai indeaproape la regiunea organelor filiere a paianjenului. Prin urmare, matasea iese din organul filier si pentru noi biologii, acesta este ceea ce noi numim partea dorsala a paianjenului. (Rasete) Asteptam zile intregi... Hei! Nu radeti! Asta mi-e viata. (Rasete) Stam zile si nopti intregi uitandu-ne la partea dorsala a paianjenului. Si asta e ceea ce vedem. Putem vedea fibre multiple iesind din oganul filiere, pentru ca fiecare organ filier contine mai mule supape . Fiecare dintre aceste fibre de matase ies prin supape, si daca ar fi sa mergeti pe urma firului inauntru in corpul paianjenului, veti observa ca fiecare supapa este conectata la propria sa glanda Glanda arata ca un saculet plin cu proteine indesate inauntru. Deci, daca veti avea vreodata posibilitatea sa disecati un paianjen tesator de panza sferica si sper ca veti avea posibilitatea, ceea ce veti gasi inauntru, in mod recompensator, sunt glandele de matase frumoase si translucide.
Inside each spider, there are hundreds of silk glands, sometimes thousands. These can be grouped into seven categories. They differ by size, shape, and sometimes even color. In an orb-web-weaving spider, you can find seven types of silk glands, and what I have depicted here in this picture, let's start at the one o'clock position, there's tubuliform silk glands, which are used to make the outer silk of an egg sac. There's the aggregate and flagelliform silk glands which combine to make the sticky capture spiral of an orb web. Pyriform silk glands make the attachment cement -- that's the silk that's used to adhere silk lines to a substrate. There's also aciniform silk, which is used to wrap prey. Minor ampullate silk is used in web construction. And the most studied silk line of them all: major ampullate silk. This is the silk that's used to make the frame and radii of an orb web, and also the safety trailing dragline.
In fiecare paianjen, exista sute de glande de matase, uneori mii. Acestea pot fi grupate in sapte categorii. Ele se deosebesc prin marime, forma si uneori chiar culoare. Intr-un paianjen de panza circulara, putem gasi sapte tipuri de glande de matase si este ceea ce vreau sa va arat in aceasta imagine, sa incepem cu pozitia 1, gasim aici matasea gladulei tubiliformes care sintetizeaza matasea pentru fabricarea matasii exterioare a coconilor pentru oua. Exista matasea gladulei aggregata si matasea glandulei flageliform care se combina in scopul de a aplica prin lipire spiralele pe scheletul panzei. Matasea glandulei pyriformes sintetizeaza fire pentru fixarea panzei- aceasta e matasea care e utilizata pentru aderarea firelor de matase la o reactie chimica. Gasim, de asemenea, gladula matasei aciniformes care este utilizata pentru a infasura prada. Matasea ampulei minore este folosita in contructia panzei. Dar cel mai studiat fir de matase dintre toate este ampula majora de matase Aceasta reprezinta matasea din care e realizat scheletul si radiile unei panze circulare, si de asemenea firul de deplasare.
But what, exactly, is spider silk? Spider silk is almost entirely protein. Nearly all of these proteins can be explained by a single gene family, so this means that the diversity of silk types we see today is encoded by one gene family, so presumably the original spider ancestor made one kind of silk, and over the last 380 million years, that one silk gene has duplicated and then diverged, specialized, over and over and over again, to get the large variety of flavors of spider silks that we have today. There are several features that all these silks have in common. They all have a common design, such as they're all very long -- they're sort of outlandishly long compared to other proteins. They're very repetitive, and they're very rich in the amino acids glycine and alanine. To give you an idea of what a spider silk protein looks like, this is a dragline silk protein, it's just a portion of it, from the black widow spider. This is the kind of sequence that I love looking at day and night. (Laughter)
Dar ce anume inseamna matasea paianjenului? Matasea paianjenului este proteina aproape in intregime. Aproape toate aceste proteine pot fi explicate printr-o singura gena familiala, deci asta inseamna ca diversitatea tipurilor de matase pe care o observam azi este criptata intr-o singura gena familiala deci in mod prezumtiv, paianjenul ancestral producea un singur tip de matase si de-a lungul a peste 380 de milioane de ani aceasta unica gena de matase s-a divizat, apoi a creat divergente, apoi s-a specializat, iarasi si iarasi si iarasi pana a ajuns la aceasta varietate a matasei de paianjen pe care o observam azi. Exista o serie de trasaturi pe care aceste tipuri de matase le au in comun. Toate au un aspect comun, in sensul ca toate sunt foarte lungi- adica sunt neobisnuit de lungi in comparatie cu alte proteine. Sunt foarte repetitive si foarte bogate in aminoacizi, glicine si alanine. Ca sa va dau o idee despre cum arata proteina din matasea paianjenului, acesta este un fir de deplasare si e doar o bucatica preluata de la o vaduva neagra. Asta este genul de secventa la care-mi place sa ma uit zi si noapte. (Rasete)
So what you're seeing here is the one letter abbreviation for amino acids, and I've colored in the glycines with green, and the alanines in red, and so you can see it's just a lot of G's and A's. You can also see that there's a lot of short sequence motifs that repeat over and over and over again, so for example there's a lot of what we call polyalanines, or iterated A's, AAAAA. There's GGQ. There's GGY. You can think of these short motifs that repeat over and over again as words, and these words occur in sentences. So for example this would be one sentence, and you would get this sort of green region and the red polyalanine, that repeats over and over and over again, and you can have that hundreds and hundreds and hundreds of times within an individual silk molecule.
Deci ceea ce vedeti aici este o abreviere pentru aminoacizi si am colorat glicinele in verde, si alaninele in rosu, astfel puteti vedea ca exista o multime de G-uri si A-uri Puteti de-asemenea sa observati ca exista si secvente mai scurte care se repeta mereu de exemplu exista o multime de ceea ce noi numim poli alanine, sau notate cu AAAAA. Exista GGQ. Exista GGY. Luati aminte la aceste modele care se repeta iar si iar ca si cuvinte, iar aceste cuvinte apar in propozitii. De exemplu, aceasta ar putea fi considerata o propozitie si atunci vom avea acest tip de zona verde iar polianinele rosii, care se repeta iar si iar si iar din nou. apoi putem avea acest lucru de sute si sute si sute de ori in interiorul unei singure molecule de matase.
Silks made by the same spider can have dramatically different repeat sequences. At the top of the screen, you're seeing the repeat unit from the dragline silk of a garden argiope spider. It's short. And on the bottom, this is the repeat sequence for the egg case, or tubuliform silk protein, for the exact same spider. And you can see how dramatically different these silk proteins are -- so this is sort of the beauty of the diversification of the spider silk gene family. You can see that the repeat units differ in length. They also differ in sequence. So I've colored in the glycines again in green, alanine in red, and the serines, the letter S, in purple. And you can see that the top repeat unit can be explained almost entirely by green and red, and the bottom repeat unit has a substantial amount of purple. What silk biologists do is we try to relate these sequences, these amino acid sequences, to the mechanical properties of the silk fibers.
Matasea produsa de acelasi paianjen poate avea in mod remarcabil, diferite secvente repetitive. In partea de sus a ecranului, puteti vedea unitatea repetitiva a firului de matase pentru deplasare a unui paianjen de gradina. E scurt. Iar in partea de jos aceasta reprezinta secventa repetitiva pentru matasea folosita in fabricarea coconilor pentru oua a aceluiasi paianjen. Si atunci puteti observa cat de diferite sunt aceste proteine de matase - deci asta reprezinta un fel de frumusete a diversitatii familiei genelor de matase a paianjenilor. Puteti observa ca unitatile repetitive difera ca lungime. Ele difera si ca secvente. Deci am colorat glicinele din nou in verde, alaninele in rosu, iar sericinele, litera S, in mov. Puteti observa ca unitatea repetitiva din partea de sus poate fi explicata aproape in intregime prin verde si rosu, iar unitatea repetitiva din partea de jos are o substantiala cantitate de mov. Ceea noi biologii matasii facem este ca incercam sa asociem aceste secvente de aminoacizi cu proprietatile mecanice ale fibrelor de matase.
Now, it's really convenient that spiders use their silk completely outside their body. This makes testing spider silk really, really easy to do in the laboratory, because we're actually, you know, testing it in air that's exactly the environment that spiders are using their silk proteins. So this makes quantifying silk properties by methods such as tensile testing, which is basically, you know, tugging on one end of the fiber, very amenable. Here are stress-strain curves generated by tensile testing five fibers made by the same spider. So what you can see here is that the five fibers have different behaviors. Specifically, if you look on the vertical axis, that's stress. If you look at the maximum stress value for each of these fibers, you can see that there's a lot of variation, and in fact dragline, or major ampullate silk, is the strongest of these fibers. We think that's because the dragline silk, which is used to make the frame and radii for a web, needs to be very strong.
Deci este foarte convenabil ca paianjenii isi utilizeaza matasea complet in afara corpului. Acest lucru face ca testarea matasii paianjenului sa fie foarte usor de realizat in laborator, pentru ca de fapt, stiti, noi o testam in aer care este exact mediul in care paianjenii isi utilizeaza proteinele matasei. Așadar așa se pot cuantifica proprietățile mătăsii prin metode precum testarea elasticitatii, care inseamna de fapt, dupa cum stiti, tragerea firului de la unul dintre capete, extrem de maleabilă. Aici avem graficul curbelor de efort generate de testarea elasticitatii a cinci fibre produse de acelasi paianjen. Deci ceea ce puteti vedea aici este ca aceste 5 fibre se comporta diferit. Mai ales, daca va uitati pe axa verticala, legata de efort. Daca va uitati la valoarea maxima a efortului pentru fiecare dintre aceste fibre, veti observa ca exista multe oscilatii, ca de fapt firul de deplasare, ori firul de matase principal, este cel mai puternic dintre toate aceste fibre. Cosideram acest lucru fiindca firul de deplasare care este utilizat pentru a construi scheletul si radiile unei panze, trebuie sa fie foarte puternic.
On the other hand, if you were to look at strain -- this is how much a fiber can be extended -- if you look at the maximum value here, again, there's a lot of variation and the clear winner is flagelliform, or the capture spiral filament. In fact, this flagelliform fiber can actually stretch over twice its original length. So silk fibers vary in their strength and also their extensibility. In the case of the capture spiral, it needs to be so stretchy to absorb the impact of flying prey. If it wasn't able to stretch so much, then basically when an insect hit the web, it would just trampoline right off of it. So if the web was made entirely out of dragline silk, an insect is very likely to just bounce right off. But by having really, really stretchy capture spiral silk, the web is actually able to absorb the impact of that intercepted prey.
Pe de alta parte, daca e sa ne uitam la capacitatea de intindere, daca ne uitam la valoarea maxima de aici, din noi, gasim multe oscilatii iar pe deplin castigator este gladula flageliform sau captura filamentului spiralei. De fapt, fibra flageliforma poate sa se intinda de fapt de doua ori decat lungimea sa originala Deci fibrele de matase variaza in functie de taria dar si de extensibilitatea lor. In cazul captarii spiralei trebuie sa fie elastica pentru a absorbi impactul cu prada zburatoare. Daca nu ar fi capabila sa se intinda atat de mult, atunci de fapt, cand o insecta se izbeste de panza aceasta ar proiecta-o imediat inapoi. Deci, daca panza ar fi facuta in intregime din din fire pentru deplasare, ar fi foarte probabil ca o insecta sa ricoseze de pe ea. Dar avand matase foarte, foarte elastica pentru captura spiralei, panza este de fapt capabila sa absoarba impactul prazii interceptate.
There's quite a bit of variation within the fibers that an individual spider can make. We call that the tool kit of a spider. That's what the spider has to interact with their environment. But how about variation among spider species, so looking at one type of silk and looking at different species of spiders? This is an area that's largely unexplored but here's a little bit of data I can show you. This is the comparison of the toughness of the dragline spilk spun by 21 species of spiders. Some of them are orb-weaving spiders and some of them are non-orb-weaving spiders. It's been hypothesized that orb-weaving spiders, like this argiope here, should have the toughest dragline silks because they must intercept flying prey. What you see here on this toughness graph is the higher the black dot is on the graph, the higher the toughness.
Exista o anumita variatie in ceea ce priveste fibrele pe care un paianjen e in stare sa le produca. Noi numim asta trusa de unelte a paianjenului. Asta este ceea ce paianjenul detine pentru a interactiona cu mediul sau. Ce-ar fi sa vorbim despre variatia dintre speciile de paianjen, adica analizand un anumit timp de matase, de la diferite specii de paianjeni? Aceasta este o zona care e inca neexplorata dar exista cateva informatii pe care vi le pot arata. Aceasta este o comparare a rezistentei firului de deplasare obtinut de la 21 de specii de paianjeni. Unii dintre ei isi tes panza circular iar altii isi tes panza haotic. Există unele ipoteze cum că paianjenii tesatori de panza circulara, precum cei din specia Argiope de aici, ar trebui sa aiba cel mai puternic fir de deplasare pentru ca ei trebuie sa intercepteze prada zburatoare. Ceea ce vedeti in acest grafic al rezistentei este aceea ca cu cat punctul negru este mai sus, cu atat rezistenta este mai mare.
The 21 species are indicated here by this phylogeny, this evolutionary tree, that shows their genetic relationships, and I've colored in yellow the orb-web-weaving spiders. If you look right here at the two red arrows, they point to the toughness values for the draglines of nephila clavipes and araneus diadematus. These are the two species of spiders for which the vast majority of time and money on synthetic spider silk research has been to replicate their dragline silk proteins. Yet, their draglines are not the toughest. In fact, the toughest dragline in this survey is this one right here in this white region, a non orb-web-weaving spider. This is the dragline spun by scytodes, the spitting spider. Scytodes doesn't use a web at all to catch prey. Instead, scytodes sort of lurks around and waits for prey to get close to it, and then immobilizes prey by spraying a silk-like venom onto that insect. Think of hunting with silly string. That's how scytodes forages. We don't really know why scytodes needs such a tough dragline, but it's unexpected results like this that make bio-prospecting so exciting and worthwhile. It frees us from the constraints of our imagination.
Cele 21 de specii sunt indicate aici de catre filogenie, acest copac evolutionist, care arata relatiile lor genetice, si am colorat in galben paianjenii cu panza circulara. Daca aruncati o privire aici la cele doua sageti rosii, ele arata valorile rezistentei pentru firul de deplasare al paianjenului auriu si al paianjenului european de gradina. Acestea sunt cele doua specii de paianjen in care se investesc timp si bani, investitii in cercetarea matasii sintetice si in copierea proteinelor firului de deplasare. Totusi, firul lor de deplasare nu este cel mai rezistent. De fapt, cel mai rezistent fir de deplasare din acest studiu este acesta de aici din aceasta regiune alba, a unui paiajen tesator de panza haotica. Acesta este firul de deplasare produs de cei din familia Scytodidelor, al păianjenului scuipător. Scytodidele nu utilizeaza deloc panza ca sa prinda prada. In schimb, Scytodidele mai degraba pandesc inprejurimile asteptand ca prada sa fie suficient de aproape, si apoi o imobilizeaza prin pulverizarea unei matase veninoase deasupra insectei. Ganditi-va ca vanati cu o funie neindemanatica. In acest mod se hranesc scytodidele. Realmente nu stim de ce scytodidele au nevoie de un astfel de fir de deplasare dar tocmai aceste rezultate neasteptate ca acestea fac fac bioprospectarea atat de interesanta si merituoasa. Ne elibereaza de sub constrangerile imaginatiei noastre.
Now I'm going to mark on the toughness values for nylon fiber, bombyx -- or domesticated silkworm silk -- wool, Kevlar, and carbon fibers. And what you can see is that nearly all the spider draglines surpass them. It's the combination of strength, extensibility and toughness that makes spider silk so special, and that has attracted the attention of biomimeticists, so people that turn to nature to try to find new solutions. And the strength, extensibility and toughness of spider silks combined with the fact that silks do not elicit an immune response, have attracted a lot of interest in the use of spider silks in biomedical applications, for example, as a component of artificial tendons, for serving as guides to regrow nerves, and for scaffolds for tissue growth.
Acum voi puncta asupra valorilor rezistentei fibrei de nailon, matasea Bombyx - sau viermii domestici de matase - fibra sintetica Kevlar, si fibrele de carbon. Si ceea ce puteti observa este ca aproape toate firele de deplasare ale paianjenilor le depaseste in valoare. Tocmai combinatia dintre putere, elasticitate si rezistenta face ca matasea paianjenilor sa fie atat de speciala, si asta e ceee ce atrage atentia biomimeticilor, oamenilor care analizeaza natura pentru a incerca sa gaseasca noi solutii. Iar puterea, elasticitatea si rezistenta matasii de paianjen combinata cu faptul ca matasea nu obtine un raspuns imun. atrage un mare interes in utilizarea matasii paianjenilor in aplicatiile biomedicale de exemplu, ca si component al tendoanelor artificiale, pentu a servi ca indiciu in refacerea nervurilor si pentru schele in cresterea de tesut.
Spider silks also have a lot of potential for their anti-ballistic capabilities. Silks could be incorporated into body and equipment armor that would be more lightweight and flexible than any armor available today. In addition to these biomimetic applications of spider silks, personally, I find studying spider silks just fascinating in and of itself. I love when I'm in the laboratory, a new spider silk sequence comes in. That's just the best. (Laughter) It's like the spiders are sharing an ancient secret with me, and that's why I'm going to spend the rest of my life studying spider silk. The next time you see a spider web, please, pause and look a little closer. You'll be seeing one of the most high-performance materials known to man. To borrow from the writings of a spider named Charlotte, silk is terrific.
Matasea paianjenilor dispune de mult potential in capacitatile ei anti-balistice. Matasea poate fi incorporata in corpul si echipamentul armurilor, pe care le-ar face mult mai usoare si mai flexibile decat orice alta armura existenta in zilele noastre. Pe langa aceste aplicatii biomimetice ale mătăsii de păianjen, personal, găsesc studierea mătăsii păianjenilor fascinanta prin ea insasi. Imi place cand in laborator fiind, o noua secventa de matase de paianjen soseste. Asta e cel mai grozav lucru. (Rasete) E ca si cum paianjenii imi destainuie un secret ancestral, si de aceea imi voi dedica restul vietii in studiul matasii de paianjen Data viitoare cand veti observa o panza de paianjen, va rog sa faceti o pauza si sa va uitati mai indeaproape. Veti vedea una dintre cele mai performante materiale cunoscute omului. In acord cu scrierile unui paianjen numit Charlotte, matasea este nemaipomenita.
Thank you. (Applause)
Multumesc (Aplauze)
(Applause)
(Aplauze)