Researchers Study Spider Silks
[00:01.31] Cheryl Hayashi began examining the body
[00:05.06] of a silver garden spider under her microscope.
[00:10.55] Using two sets of tweezers, she soon found what she was looking for:
[00:17.31] hundreds of silk glands, the organs spiders use to make their webs.
[00:25.05] Each gland lets a spider produce a different type of silk.
[00:31.31] "They [spiders] make so many kinds of silk!" Hayashi said.
[00:36.06] "That's just what boggles my mind."
[00:39.81] Hayashi's lab at the American Museum of Natural History
[00:45.06] is studying the genes behind each kind of silk.
[00:50.30] She has collected spider silk glands of about 50 species.
[00:56.30] The goal is to make a kind of "silk library," she said.
[01:02.31] The library could become an important information resource
[01:07.56] for designing new products from space equipment to clothing.
[01:13.80] However, the library's work is far from complete.
[01:19.30] There are more than 48,000 spider species known worldwide.
[01:25.81] Spider silks all start out in the same way:
[01:30.81] as a wet and sticky substance.
[01:34.80] It is like rubber cement or thick honey, as Hayashi describes it.
[01:40.81] Spiders make the substance and store it in a gland until they want to make silk.
[01:48.31] Then, a short tube called a spigot opens.
[01:53.81] As the substance flows out, it changes into a solid silk strand
[02:00.06] that joins with other strands coming from other spigots.
[02:05.56] Nobody knows how many kinds of spider silks exist.
[02:11.30] But, some species can produce many kinds.
[02:16.31] Orb-weaving spiders, for example, make seven kinds.
[02:21.30] Hayashi has been studying spider silk for about 20 years.
[02:27.56] Only recently has improved technology
[02:31.55] let scientists quickly study the genetic material, or DNA,
[02:37.81] of spiders and produce synthetic spider silk in large amounts.
[02:44.06] Until recently, scientists had to first cut the glands' DNA into pieces.
[02:52.81] They then used a computer to try to put the DNA back in order,
[02:58.30] like a jigsaw puzzle.
[03:01.55] The task is especially difficult for the DNA of spiders
[03:06.30] because their genes are very long and repetitive.
[03:10.81] That is the problem Sarah Stellwagen from the University of Maryland, Baltimore County faced.
[03:20.06] She was studying genes, and DNA, related to spider silk.
[03:27.05] She thought she could do it quickly,
[03:29.80] but it took almost two years.
[03:33.05] Scientists have to recover the full gene
[03:37.06] to truly copy natural silk, she said.
[03:41.55] If they try to produce silk from only part of a gene
[03:45.56] or something produced in a laboratory,
[03:49.05] "it's not as good as what a spider makes," Stellwagen said.
[03:54.81] It was only last year that a research group
[03:58.30] was able to make a small amount of silk
[04:01.81] that perfectly matched the kind of silk that an orb-weaving spider dangles from.
[04:09.06] But that was only one kind of silk from one species.
[04:15.06] Hayashi asked: "What about the other 48,000?"
[04:20.80] As technology has improved,
[04:23.81] researchers can now map genes much better
[04:27.56] without first chopping them up.
[04:31.05] And companies have gotten closer
[04:33.31] to successfully recreating spider silks.
[04:38.06] Now, the task remains to discover the secrets
[04:42.05] of the thousands of other spider silks out there,
[04:46.31] which is not easy.
[04:48.80] "But hey, you know,
[04:50.80] we all have goals," Hayashi said.
[04:53.56] I'm John Russell.
