Changes in element composition along the spinning duct in a Nephila spider

  title={Changes in element composition along the spinning duct in a Nephila spider},
  author={David P. Knight and Fritz Vollrath},
Abstract. The silk gland of the golden orb spider Nephila edulis connects to the exit spigot through a long S-shaped duct that assists in the formation of the thread. Previous evidence suggests that the epithelium of the distal (last) part of the duct is specialized for ion transport and that a proton pump is involved in this process. Here, we present evidence from SEM (scanning electron microscope)-EDAX (energy dispersive X-ray) microanalysis of rapidly frozen material maintained at… 
Morphology and composition of the spider major ampullate gland and dragline silk.
It is shown that NT is present in the dope and throughout dragline silk fibers, including the skin layer, and that the major ampullate tail and sac consist of three different and sharply demarcated zones (A-C), each with a distinct epithelial cell type.
Probing the Impact of Acidification on Spider Silk Assembly Kinetics.
The results confirm the importance of an acidic pH gradient along the spinning duct for spider silk formation and provide a powerful spectroscopic approach to probe the kinetics of spider Silk formation under various biochemical conditions.
Differential polymerization of the two main protein components of dragline silk during fibre spinning
The findings suggest that the role of spidroin 2 in the spinning process could be to facilitate the formation of fibrils and contribute directly to the elasticity of the silk.
Spidroin N-terminal Domain Promotes a pH-dependent Association of Silk Proteins during Self-assembly*
It is shown that the N-terminal domain of spidroins from the major ampullate gland (MaSp-NTDs) for both Nephila and Latrodectus spiders associate noncovalently as homodimers.
Combining flagelliform and dragline spider silk motifs to produce tunable synthetic biopolymer fibers
Nuclear magnetic resonance indicated that the fraction of β‐sheet nanocrystals in the polyalanine regions formed upon extrusion, increased during stretching, and was maximized after water‐treatment, and X‐ray diffraction showed that nanocrystallite orientation parallel to the fiber axis increased the ultimate strength and initial stiffness of the fibers.
A New Evidence of Lubrication Hypothesis on Nephila pilipes Spider Silk Spinning
A novel approach to quantitatively estimate the overall concentration change of spider silk along the progression of liquid-to-solid silk transition from the gland silk and a hypothesis of liquid coating on the outer surface of the silk thread served as a lubrication layer to reduce the silking resistance in spinning spigot of spider was proposed.
A Facile Measurement for Monitoring Dragline Silk Dope Concentration in Nephila pilipes upon Spinning
In spite of all the efforts towards deciphering the silk spinning process of spiders, the underlying mechanism is yet to be fully revealed. In this research, we designed a novel approach that allowed
Structure and pH‐induced alterations of recombinant and natural spider silk proteins in solution
Using a combination of NMR and dynamic light scattering, it is found that the spectral alteration of glycine is concomitant to a modification of the hydrodynamical diameter of recombinant and solubilized MaS.
The Secretion Process of Liquid Silk with Nanopillar Structures from Stenopsyche marmorata (Trichoptera: Stenopsychidae)
The morphological characteristics suggest that the silk insolubilization leading to fibrillation occurs by luminal pH neutralization, and nanopillar structures probably contribute to the strong underwater adhesion of S. marmorata silk.


Structure and function of the silk production pathway in the spider Nephila edulis.
The ampullate silk gland of the spider, Araneus sericatus, produces the silk fiber for the scaffolding of the web. The fine structure of the various parts of the gland is described. The distal
Silk production in a spider involves acid bath treatment
It appears that spider silk in vivo, like some industrial polymers in vitro, is spun through an acid bath.
Liquid crystals and flow elongation in a spider's silk production line
  • D. Knight, F. Vollrath
  • Materials Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1999
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
Liquid crystalline spinning of spider silk
Successful copying of the spider's internal processing and precise control over protein folding, combined with knowledge of the gene sequences of its spinning dopes, could permit industrial production of silk-based fibres with unique properties under benign conditions.
Simultaneous comparison of techniques for x-ray analysis of proximal tubule cells.
The differing values previously reported for elemental analysis of rat kidney cannot be ascribed to either cryosectioning at a warmer temperature or to the analytical algorithm used by either group.
H + V-ATPases Energize Animal Plasma Membranes for Secretion and Absorption of Ions and Fluids'
H+ V-ATPases are well known energizers of endomembranes; thus they play a key role in the acidification of vacuoles and vesicles and are likely that apical membranes of fresh water fish and other animals that live in media in which the concentration of Na+ is low, are also energized by H+ V− ATPases.
Rat renal papilla: comparison of two techniques for x-ray analysis.
The results demonstrated two major problems with application of an albumin peripheral standard: 1) albumin dipping significantly changed elemental and water content in papillary collecting duct cells, epithelial cells and interstitium, but interstitial cells were not affected; 2) the peripheral albumin standard itself changed water and elemental content in a direction consistent with movement of Na and Cl from tissue to standard, and water from standard to tissue.