title: High-toughness silk produced by a transgenic silkworm expressing spider (Araneus ventricosus) dragline silk protein.
abstract: Spider dragline silk is a natural fiber that has excellent tensile properties; however, it is difficult to produce artificially as a long, strong fiber. Here, the spider (Araneus ventricosus) dragline protein gene was cloned and a transgenic silkworm was generated, that expressed the fusion protein of the fibroin heavy chain and spider dragline protein in cocoon silk. The spider silk protein content ranged from 0.37 to 0.61% w/w (1.4-2.4 mol%) native silkworm fibroin. Using a good silk-producing strain, C515, as the transgenic silkworm can make the raw silk from its cocoons for the first time. The tensile characteristics (toughness) of the raw silk improved by 53% after the introduction of spider dragline silk protein; the improvement depended on the quantity of the expressed spider dragline protein. To demonstrate the commercial feasibility for machine reeling, weaving, and sewing, we used the transgenic spider silk to weave a vest and scarf; this was the first application of spider silk fibers from transgenic silkworms.
authors.affiliation: Silk Materials Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kuwana
authors.affiliation: Transgenic Silkworm Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Sezutsu
authors.affiliation: Transgenic Silkworm Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Silk Materials Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan; Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Tamada
authors.affiliation: Silk Materials Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Katsura
authors.initials: K
authors.lastname: Kojima
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D005349:Fibroins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D015870:Gene Expression; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D007814:Larva / Q000235:genetics / Q000378:metabolism; D008422:Materials Testing; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D013112:Spiders / Q000737:chemistry* / Q000378:metabolism; D013718:Tensile Strength; D013784:Textiles / Q000600:supply & distribution
chemical_list: D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; C482288:fibroin, silkworm; D049452:Green Fluorescent Proteins; C076815:spidroin 2; D005349:Fibroins