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Ultrastructure of spider thread anchorages.
Wirth, Marina; Wolff, Jonas O; Appel, Esther; Gorb, Stanislav N.
Afiliación
  • Wirth M; Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, Am Botanischen Garten 9, Kiel, Germany.
  • Wolff JO; Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, Am Botanischen Garten 9, Kiel, Germany.
  • Appel E; Department of Biological Sciences, Macquarie University, Sydney, Australia.
  • Gorb SN; Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, Am Botanischen Garten 9, Kiel, Germany.
J Morphol ; 280(4): 534-543, 2019 04.
Article en En | MEDLINE | ID: mdl-30791126
Spiders attach silken threads to substrates by means of glue-coated nanofibers (piriform silk), spun into disc-like structures. The organization and ultrastructure of this nano-composite silk are largely unknown, despite their implications for the biomechanical function and material properties of thread anchorages. In this work, the ultrastructure of silken attachment discs was studied in representatives of four spider families with Transmission Electron Microscopy to facilitate a mechanistic understanding of piriform silk function across spiders. Based on previous findings from comparative studies of piriform silk gland morphology, we hypothesized that the fibre-glue proportion of piriform silk differs in different spiders, while the composition of fibre and glue fractions is consistent. Results confirmed large differences in the relative proportion of glue with low amounts in the orb weaver Nephila senegalensis (Araneidae) and the hunting spider Cupiennius salei (Ctenidae), larger amounts in the cobweb spider Parasteatoda tepidariorum (Theridiidae) and a complete reduction of the fibrous component in the haplogyne spider Pholcus phalangioides (Pholcidae). We rejected our hypothesis that glue ultrastructure is consistent. The glue is a colloid with polymeric and fluid fractions that strongly differ in proportions and assembly. We further confirmed that in all species studied both dragline and piriform silk fibres do not make contact with the environmental substrate. Instead, adhesion is established by a thin dense skin layer of the piriform glue. These results advance our understanding of piriform silk function and the interspecific variation of its properties, which is significant for spider biology, web function and the bioengineering of silk.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Arañas / Seda Límite: Animals Idioma: En Revista: J Morphol Año: 2019 Tipo del documento: Article País de afiliación: Alemania Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Arañas / Seda Límite: Animals Idioma: En Revista: J Morphol Año: 2019 Tipo del documento: Article País de afiliación: Alemania Pais de publicación: Estados Unidos