Author:Nobuaki Kono1,2, Rintaro Ohtoshi3, Ali D. Malay3, Masaru Mori1,2, Hiroyasu Masunaga4,5, Yuki Yoshida1,2, Hiroyuki Nakamura6, Keiji Numata3,7 and Kazuharu Arakawa1,2
- 1. Institute for Advanced Biosciences, Keio University
- 2. Systems Biology Program, Graduate School of Media and Governance, Keio University
- 3. RIKEN Center for Sustainable Resource Science
- 4. Japan Synchrotron Radiation Research Institute
- 5. RIKEN SPring-8 Center/li>
- 6. Spiber Inc.
- 7. Department of Material Chemistry, Kyoto University
From “Darwin’s bark spider shares a spidroin repertoire with Caerostris extrusa but achieves extraordinary silk toughness through gene expression” by Kono et al.. Licensed under CC-BY 4.0.
Spider silk is a protein-based material whose toughness suggests possible novel applications. A particularly fascinating example of silk toughness is provided by Darwin’s bark spider (Caerostris darwini) found in Madagascar. This spider produces extraordinarily tough silk, with an average toughness of 350 MJ m−1 and over 50% extensibility, and can build river-bridging webs with a size of 2.8 m2. Recent studies have suggested that specific spidroins expressed in C. darwini are responsible for the mechanical properties of its silk. Therefore, a more comprehensive investigation of spidroin sequences, silk thread protein contents and phylogenetic conservation among closely related species is required. Here, we conducted genomic, transcriptomic and proteomic analyses of C. darwini and its close relative Caerostris extrusa. A variety of spidroins and low-molecular-weight proteins were found in the dragline silk of these species; all of the genes encoding these proteins were conserved in both genomes, but their genes were more expressed in C. darwini. The potential to produce very tough silk is common in the genus Caerostris, and our results may suggest the existence of plasticity allowing silk mechanical properties to be changed by optimizing related gene expression in response to the environment.
本研究の遂行に際し、当社は 内閣府 革新的研究開発推進プログラム（ImPACT）「超高機能構造タンパク質による素材産業革命」 の助成を受けました。