The Experts below are selected from a list of 396 Experts worldwide ranked by ideXlab platform
Gea Guerriero - One of the best experts on this subject based on the ideXlab platform.
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Putative Chitin Synthases from Branchiostoma floridae Show Extracellular Matrix-related Domains and Mosaic Structures
Genomics Proteomics & Bioinformatics, 2012Co-Authors: Gea GuerrieroAbstract:The transition from unicellular to multicellular life forms requires the development of a specialized structural component, the extracellular matrix (ECM). In Metazoans, there are two main supportive systems, which are based on chitin and collagen/hyaluronan, respectively. Chitin is the major constituent of fungal cell walls and Arthropod Exoskeleton. However, presence of chitin/chitooligosaccharides has been reported in lower chordates and during specific stages of vertebrate development. In this study, the occurrence of chitin synthases (CHSs) was investigated with a bioinformatics approach in the cephalochordate Branchiostoma floridae, in which the presence of chitin was initially reported in the skeletal rods of the pharyngeal gill basket. Twelve genes coding for proteins containing conserved amino acid residues of processive glycosyltransferases from GT2 family were found and 10 of them display mosaic structures with novel domains never reported previously in a chitin synthase. In particular, the presence of a discoidin (DS) and a sterile alpha motif (SAM) domain was found in nine identified proteins. Sequence analyses and homology modelling suggest that these domains might interact with the extracellular matrix and mediate protein–protein interaction. The multi-domain putative chitin synthases from B. floridae constitute an emblematic example of the explosion of domain innovation and shuffling which predate Metazoans.
David Kisailus - One of the best experts on this subject based on the ideXlab platform.
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biomimetic structural materials inspiration from design and assembly
Annual Review of Physical Chemistry, 2018Co-Authors: Nicholas A Yaraghi, David KisailusAbstract:Nature assembles weak organic and inorganic constituents into sophisticated hierarchical structures, forming structural composites that demonstrate impressive combinations of strength and toughness. Two such composites are the nacre structure forming the inner layer of many mollusk shells, whose brick-and-mortar architecture has been the gold standard for biomimetic composites, and the cuticle forming the Arthropod Exoskeleton, whose helicoidal fiber-reinforced architecture has only recently attracted interest for structural biomimetics. In this review, we detail recent biomimetic efforts for the fabrication of strong and tough composite materials possessing the brick-and-mortar and helicoidal architectures. Techniques discussed for the fabrication of nacre- and cuticle-mimetic structures include freeze casting, layer-by-layer deposition, spray deposition, magnetically assisted slip casting, fiber-reinforced composite processing, additive manufacturing, and cholesteric self-assembly. Advantages and limita...
Ronellenfitsch Henrik - One of the best experts on this subject based on the ideXlab platform.
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Optimal elasticity of biological networks
'American Physical Society (APS)', 2020Co-Authors: Ronellenfitsch HenrikAbstract:Reinforced elastic sheets surround us in daily life, from concrete shell buildings to biological structures such as the Arthropod Exoskeleton or the venation network of dicotyledonous plant leaves. Natural structures are often highly optimized through evolution and natural selection, leading to the biologically and practically relevant problem of understanding and applying the principles of their design. Inspired by the hierarchically organized scaffolding networks found in plant leaves, here we model networks of bending beams that capture the discrete and non-uniform nature of natural materials. Using the principle of maximal rigidity under natural resource constraints, we show that optimal discrete beam networks reproduce the structural features of real leaf venation. Thus, in addition to its ability to efficiently transport water and nutrients, the venation network also optimizes leaf rigidity using the same hierarchical reticulated network topology. We study the phase space of optimal mechanical networks, providing concrete guidelines for the construction of elastic structures. We implement these natural design rules by fabricating efficient, biologically inspired metamaterials.Comment: 5 pages, 4 figures, supplemental materia
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Optimal elastic networks and the natural design of plant leaves
2020Co-Authors: Ronellenfitsch HenrikAbstract:Reinforced elastic sheets surround us in daily life, from concrete shell buildings over cars and airplane fuselages to biological structures such as the Arthropod Exoskeleton or the venation network of dicotyledonous plant leaves. Natural structures are often highly optimized through evolution and natural selection, leading to the biologically and practically relevant problem of understanding and applying the principles of their design. Inspired by the hierarchically organized scaffolding networks found in plant leaves, here we model networks of bending beams that capture the discrete and non-uniform nature of biologically evolved mechanical structures. Using the principle of maximal rigidity under natural resource constraints, we show that optimal discrete beam networks reproduce the structural features of real leaf venation. Thus, in addition to its ability to efficiently transport water and nutrients, the venation network optimizes leaf mechanical properties using practically the same hierarchical reticulated network topology. We study the phase space of optimal mechanical networks, providing concrete guidelines for the construction of elastic structures. We finally implement these natural design rules by fabricating efficient, biologically inspired metamaterials.Comment: 7 pages, 4 figures, supplemental appendi
Richard M Clark - One of the best experts on this subject based on the ideXlab platform.
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population bulk segregant mapping uncovers resistance mutations and the mode of action of a chitin synthesis inhibitor in Arthropods
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Thomas Van Leeuwen, Peter Demaeght, Edward J Osborne, Wannes Dermauw, Simon Gohlke, Ralf Nauen, Miodrag Grbic, Luc Tirry, Hans Merzendorfer, Richard M ClarkAbstract:Because of its importance to the Arthropod Exoskeleton, chitin biogenesis is an attractive target for pest control. This point is demonstrated by the economically important benzoylurea compounds that are in wide use as highly specific agents to control insect populations. Nevertheless, the target sites of compounds that inhibit chitin biogenesis have remained elusive, likely preventing the full exploitation of the underlying mode of action in pest management. Here, we show that the acaricide etoxazole inhibits chitin biogenesis in Tetranychus urticae (the two-spotted spider mite), an economically important pest. We then developed a population-level bulk segregant mapping method, based on high-throughput genome sequencing, to identify a locus for monogenic, recessive resistance to etoxazole in a field-collected population. As supported by additional genetic studies, including sequencing across multiple resistant strains and genetic complementation tests, we associated a nonsynonymous mutation in the major T. urticae chitin synthase (CHS1) with resistance. The change is in a C-terminal transmembrane domain of CHS1 in a highly conserved region that may serve a noncatalytic but essential function. Our finding of a target-site resistance mutation in CHS1 shows that at least one highly specific chitin biosynthesis inhibitor acts directly to inhibit chitin synthase. Our work also raises the possibility that other chitin biogenesis inhibitors, such as the benzoylurea compounds, may also act by inhibition of chitin synthases. More generally, our genetic mapping approach should be powerful for high-resolution mapping of simple traits (resistance or otherwise) in Arthropods.
Nicholas A Yaraghi - One of the best experts on this subject based on the ideXlab platform.
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biomimetic structural materials inspiration from design and assembly
Annual Review of Physical Chemistry, 2018Co-Authors: Nicholas A Yaraghi, David KisailusAbstract:Nature assembles weak organic and inorganic constituents into sophisticated hierarchical structures, forming structural composites that demonstrate impressive combinations of strength and toughness. Two such composites are the nacre structure forming the inner layer of many mollusk shells, whose brick-and-mortar architecture has been the gold standard for biomimetic composites, and the cuticle forming the Arthropod Exoskeleton, whose helicoidal fiber-reinforced architecture has only recently attracted interest for structural biomimetics. In this review, we detail recent biomimetic efforts for the fabrication of strong and tough composite materials possessing the brick-and-mortar and helicoidal architectures. Techniques discussed for the fabrication of nacre- and cuticle-mimetic structures include freeze casting, layer-by-layer deposition, spray deposition, magnetically assisted slip casting, fiber-reinforced composite processing, additive manufacturing, and cholesteric self-assembly. Advantages and limita...
