Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0017, Japan; Faculty of Environment and Information Studies, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan; Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan.
Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0017, Japan; Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan.
J Proteomics. 2021 May 15;239:104195. doi: 10.1016/j.jprot.2021.104195. Epub 2021 Mar 20.
Spider mites are a group of arachnids belonging to Acari (mites and ticks), family Tetranychidae, known to produce nanoscale silk fibers characterized by a high Young's modulus. The silk fibroin gene of spider mites has been computationally predicted through genomic analysis of Tetranychus urticae Koch, but it has yet to be confirmed by proteomic evidence. In this work, we sequenced and assembled the transcriptome from two genera of spider mites, Tetranychus kanzawai Kishida and Panonychus citri (McGregor), and combined it with silk proteomics of T. urticae and P. citri to characterize the fibroin genes through comparative genomics and multiomics analysis. As a result, two fibroins were identified, which were different genes than those previously predicted by computational methods. The amino acid composition and secondary structure suggest similarity to aciniform or cylindrical spidroins of spider silk, which partly mirrors their mechanical properties, exhibiting a high Young's modulus. The availability of full-length fibroin sequences of spider mites facilitates the study of the evolution of silk genes that sometimes emerge in multiple lineages in a convergent manner and in the industrial application of artificial protein fibers through the study of the amino acid sequence and the resulting mechanical properties of these silks. SIGNIFICANCE: Here we sequenced and assembled the transcriptome from two genera of spider mites, T. kanzawai and P. citri, and combined it with silk proteomics of T. urticae and P. citri to characterize the fibroin genes through comparative genomics and multiomics analysis. Spider mite silk is especially characterized by its extremely fine nano-scale diameter and high Young's modulus, even exceeding those of spider silks. The availability of full-length fibroin sequences of spider mites facilitates the study of the evolution of silk genes, which independently evolved in mites, insects, and spiders but yet show sequence convergence, and in the industrial application of artificial protein fibers through the study of the amino acid sequence and the resulting mechanical properties of these silks.
蜘蛛螨是一类属于蛛形纲（螨和蜱）的节肢动物，属于 Tetranychidae 科，已知它们能产生具有高杨氏模量的纳米级丝纤维。通过对 Tetranychus urticae Koch 的基因组分析，已经通过计算预测了蜘蛛螨的丝纤维基因，但尚未通过蛋白质组学证据得到证实。在这项工作中，我们对两种蜘蛛螨，Tetranychus kanzawai Kishida 和 Panonychus citri（McGregor）的转录组进行了测序和组装，并将其与 T. urticae 和 P. citri 的丝蛋白组学相结合，通过比较基因组学和多组学分析来描述丝纤维基因。结果鉴定出两种丝纤维，它们与以前通过计算方法预测的基因不同。氨基酸组成和二级结构表明与蜘蛛丝的 aciniform 或圆柱形丝蛋白相似，这部分反映了它们的机械性能，表现出高杨氏模量。蜘蛛螨全长丝纤维序列的可用性促进了丝基因进化的研究，丝基因有时以趋同的方式出现在多个谱系中，并且通过研究这些丝的氨基酸序列和由此产生的机械性能，促进了人工蛋白纤维的工业应用。意义：在这里，我们对两种蜘蛛螨，T. kanzawai 和 P. citri 的转录组进行了测序和组装，并将其与 T. urticae 和 P. citri 的丝蛋白组学相结合，通过比较基因组学和多组学分析来描述丝纤维基因。蜘蛛螨丝的特点是其极其细的纳米级直径和高杨氏模量，甚至超过了蜘蛛丝。蜘蛛螨全长丝纤维序列的可用性促进了丝基因进化的研究，这些基因在螨、昆虫和蜘蛛中独立进化，但表现出序列趋同，并且通过研究这些丝的氨基酸序列和由此产生的机械性能，促进了人工蛋白纤维的工业应用。
