The Experts below are selected from a list of 7587 Experts worldwide ranked by ideXlab platform
Benjamin F Voight - One of the best experts on this subject based on the ideXlab platform.
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The Nephila clavipes genome highlights the diversity of spider Silk genes and their complex expression
Nature Genetics, 2017Co-Authors: Paul L Babb, Cheryl Y. Hayashi, Nicholas F Lahens, David N Nicholson, John B Hogenesch, Linden Higgins, Matjaž Kuntner, Ingi Agnarsson, Sandra M. Correa-garhwal, Benjamin F VoightAbstract:Spider Silks are the toughest known biological materials, yet are lightweight and virtually invisible to the human immune system, and they thus have revolutionary potential for medicine and industry. Spider Silks are largely composed of spidroins, a unique family of structural proteins. To investigate spidroin genes systematically, we constructed the first genome of an orb-weaving spider: the golden orb-weaver ( Nephila clavipes ), which builds large webs using an extensive repertoire of Silks with diverse physical properties. We cataloged 28 Nephila spidroins, representing all known orb-weaver spidroin types, and identified 394 repeated coding motif variants and higher-order repetitive cassette structures unique to specific spidroins. Characterization of spidroin expression in distinct Silk gland types indicates that glands can express multiple spidroin types. We find evidence of an alternatively spliced spidroin, a spidroin expressed only in venom glands, evolutionary mechanisms for spidroin diversification, and non-spidroin genes with expression patterns that suggest roles in Silk Production. Benjamin Voight and colleagues report the annotated genome of the golden orb-weaver spider. They describe 28 spider Silk genes (spidroins), characterize their expression in distinct Silk gland types and identify non-spidroin genes with expression patterns suggesting potential roles in Silk Production.
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the nephila clavipes genome highlights the diversity of spider Silk genes and their complex expression
Nature Genetics, 2017Co-Authors: Paul L Babb, Cheryl Y. Hayashi, Nicholas F Lahens, David N Nicholson, John B Hogenesch, Linden Higgins, Sandra M Correagarhwal, Matjaž Kuntner, Ingi Agnarsson, Benjamin F VoightAbstract:Benjamin Voight and colleagues report the annotated genome of the golden orb-weaver spider. They describe 28 spider Silk genes (spidroins), characterize their expression in distinct Silk gland types and identify non-spidroin genes with expression patterns suggesting potential roles in Silk Production.
Fritz Vollrath - One of the best experts on this subject based on the ideXlab platform.
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Life cycle assessment of Silk Production – a case study from India
Handbook of Life Cycle Assessment (LCA) of Textiles and Clothing, 2015Co-Authors: Miguel F. Astudillo, Gunnar Thalwitz, Fritz VollrathAbstract:Abstract Silk is the only long natural filament fibre used in textiles. Its Production and attendant environmental issues are dissimilar from those of other textile products. Life cycle assessment (LCA) has been extensively employed to analyse textiles, however, despite its long history and unique properties as a biomaterial, the LCA literature on Silk Production is extremely limited. We present here an overview of Silk LCA results, focusing on a case study of cocoon Production and processing to raw Silk in India. Results indicate that environmental impact is higher than for most other fibres across impact categories. Hotspots and possible areas for improvement are identified.
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Life cycle assessment of Indian Silk
Journal of Cleaner Production, 2014Co-Authors: Miguel F. Astudillo, Gunnar Thalwitz, Fritz VollrathAbstract:Abstract The environmental impact of textiles is an area of increasing interest for consumers and legislators. Life cycle assessment (LCA) is the commonly used decision support tool for quantifying environmental impacts, and has been applied to most all major textiles. So far there has, however, been no cradle-to-gate assessment of raw Silk Production. On the basis of a review of literature on Silk Production, this paper constructs a first life cycle inventory of the Production of high-quality Silk under tropical conditions in southern India. Values are calculated for the following environmental impact indicators: global warming potential, ecotoxicity, freshwater eutrophication, land occupation, cumulative energy demand and blue water footprint. The functional unit is defined as 1 kg raw Silk, at factory gate. The analysis compares best practice recommendations with observed farm practices. Where applicable, data gaps have been highlighted. Results indicate that Silk Production following recommended practices is input intensive and that on a mass basis, environmental impacts are above those reported for other natural fibres. The majority of environmental impacts stem from cocoon Production, in particular fertilization. Farm practices diverge from recommendations significantly and the observed impact per functional unit is higher. The multiple stages required to manufacture raw Silk result in a large amount of co-products. Increasing the efficiency in utilisation of these could reduce the high impact observed in this study.
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spider Silk super material or thin fibre
Advanced Materials, 2013Co-Authors: David Porter, Juan Guan, Fritz VollrathAbstract:3] However, in order to judge whether Silk is, in fact, an exceptional structural material that can deliver as a commercially attractive polymer replacement in engineering applications, we need direct com-parisons of Silks with synthetic polymer fi bres on properties such as strength and toughness. This question has important consequences for industrial Silk Production routes such as Silk reconstitution (RSF),
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liquid crystals and flow elongation in a spider s Silk Production line
Proceedings of The Royal Society B: Biological Sciences, 1999Co-Authors: David P Knight, Fritz VollrathAbstract:Our observations on whole mounted major ampullate Silk glands suggested that the thread is drawn from a hyperbolic die using a pre–orientated lyotropic liquid crystalline feedstock. Polarizing microscopy of the gland's duct revealed two liquid crystalline optical textures: a curved pattern in the feedstock within the ampulla of the gland and, later in the secretory pathway, the cellular texture previously identified in synthetic nematic liquid crystals. The behaviour of droplet inclusions within the Silk feedstock indicated that elongational flow at a low shear rate occurs in the gland's duct and may be important in producing an axial molecular orientation before the final thread is drawn. Our observations suggested that the structure of the spider's Silk Production pathway and the liquid crystalline feedstock are both involved in defining the exceptional mechanical properties of spider dragline Silk.
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Silk Production in a spider involves acid bath treatment
Proceedings of The Royal Society B: Biological Sciences, 1998Co-Authors: Fritz Vollrath, David P KnightAbstract:We studied physiological conditions during the spinning of dragline Silk by the garden cross spider, Araneus diadematus . Silk is converted from the liquid feedstock in the gland into a solid thread via a tapering tubular duct and exits at a spigot. The distal part of the tubule appears specialized for ion transport and the management of the pH inside the lumen. Thus, it appears that spider Silk in vivo , like some industrial polymers in vitro , is spun through an acid bath.
Jan Johansson - One of the best experts on this subject based on the ideXlab platform.
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toward spinning artificial spider Silk
Nature Chemical Biology, 2015Co-Authors: Anna Rising, Jan JohanssonAbstract:Spider Silks have enormous potential as strong yet flexible biomaterials, but obtaining artificial Silk polymers has proven challenging. Recent advances in our understanding of natural Silk processing may inform techniques for Silk Production.
Xin Chen - One of the best experts on this subject based on the ideXlab platform.
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mass spider Silk Production through targeted gene replacement in bombyx mori
Proceedings of the National Academy of Sciences of the United States of America, 2018Co-Authors: Jun Xu, Dongfeng Ji, Muwang Li, Qinglin Dong, Ye Yu, Yongping Huang, Xin ChenAbstract:Spider Silk is one of the best natural fibers and has superior mechanical properties. However, the large-scale harvesting of spider Silk by rearing spiders is not feasible, due to their territorial and cannibalistic behaviors. The Silkworm, Bombyx mori, has been the most well known Silk producer for thousands of years and has been considered an ideal bioreactor for producing exogenous proteins, including spider Silk. Previous attempts using transposon-mediated transgenic Silkworms to produce spider Silk could not achieve efficient yields, due to variable promoter activities and endogenous Silk fibroin protein expression. Here, we report a massive spider Silk Production system in B. mori by using transcription activator-like effector nuclease-mediated homology-directed repair to replace the Silkworm fibroin heavy chain gene (FibH) with the major ampullate spidroin-1 gene (MaSp1) in the spider Nephila clavipes. We successfully replaced the ∼16-kb endogenous FibH gene with a 1.6-kb MaSp1 gene fused with a 1.1-kb partial FibH sequence and achieved up to 35.2% chimeric MaSp1 protein amounts in transformed cocoon shells. The presence of the MaSp1 peptide significantly changed the mechanical characteristics of the Silk fiber, especially the extensibility. Our study provides a native promoter-driven, highly efficient system for expressing the heterologous spider Silk gene instead of the transposon-based, random insertion of the spider gene into the Silkworm genome. Targeted MaSp1 integration into Silkworm Silk glands provides a paradigm for the large-scale Production of spider Silk protein with genetically modified Silkworms, and this approach will shed light on developing new biomaterials.
Cintya Perdomo - One of the best experts on this subject based on the ideXlab platform.
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Silk Production from tarantula feet questioned
Nature, 2009Co-Authors: Fernando Pérez-miles, Alejandra Panzera, David Ortiz-villatoro, Cintya PerdomoAbstract:Arising from: S. N. Gorb et al. Nature 443 , 407 (2006)10.1038/443407a ; Gorb et al. reply As with all spiders, tarantulas spin Silk from specialized structures in the abdomen called spinnerets, which are key features unique to the group. Recently Gorb et al. ^ 1 reported that the zebra tarantula Aphonopelma seemanni also secretes Silk from its feet, which might improve its ability to climb on vertical surfaces. Here we show that when the spinnerets are experimentally sealed, the zebra tarantula cannot secrete Silk or similar threads, disagreeing with previous reports by Gorb et al. ^ 1 . Additional evidence also disagrees with leg secretion of Silk.
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Silk Production from tarantula feet questioned.
Nature, 2009Co-Authors: Fernando Pérez-miles, Alejandra Panzera, David Ortiz-villatoro, Cintya PerdomoAbstract:Arising from: S. N. Gorb et al. , 407 (2006)10.1038/443407a ; Gorb et al. reply As with all spiders, tarantulas spin Silk from specialized structures in the abdomen called spinnerets, which are key features unique to the group. Recently Gorb et al.1 reported that the zebra tarantula Aphonopelma seemanni also secretes Silk from its feet, which might improve its ability to climb on vertical surfaces. Here we show that when the spinnerets are experimentally sealed, the zebra tarantula cannot secrete Silk or similar threads, disagreeing with previous reports by Gorb et al.1. Additional evidence also disagrees with leg secretion of Silk.