Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Biological Science Research Center, Southwest University, Chongqing 400715, China.
College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China.
Int J Mol Sci. 2024 Jun 29;25(13):7179. doi: 10.3390/ijms25137179.
The gene, crucial for silk spinning in insects, encodes a protein that significantly influences silk fiber mechanics. Due to its large size and repetitive sequences, limited known sequences of insect FibH impede comprehensive understanding. Here, we analyzed 114 complete gene sequences from Lepidoptera (71 moths, 24 butterflies) and 13 Trichoptera, revealing single-copy in most species, with 2-3 copies in Hesperinae and Heteropterinae (subfamily of skippers). All genes are structured with two exons and one intron (39-45 bp), with the second exon being notably longer. Moths exhibit higher GC content in compared to butterflies and Trichoptera. The FibH composition varies among species, with moths and butterflies favoring Ala, Gly, Ser, Pro, Gln, and Asn, while Trichoptera FibH is enriched in Gly, Ser, and Arg, and has less Ala. Unique to Trichoptera FibH are Tyr, Val, Arg, and Trp, whereas Lepidoptera FibH is marked by polyAla (polyalanine), polySer (polyserine), and the hexapeptide GAGSGA. A phylogenetic analysis suggests that Lepidoptera FibH evolved from Trichoptera, with skipper FibH evolving from Papilionoidea. This study substantially expands the FibH repertoire, providing a foundation for the development of artificial silk.
该基因对昆虫的丝纺至关重要，其编码的蛋白质对丝纤维力学有显著影响。由于其庞大的大小和重复序列，已知的昆虫 FibH 序列有限，阻碍了全面理解。在这里，我们分析了来自鳞翅目（71 种蛾类，24 种蝴蝶）和 13 种蜉蝣目昆虫的 114 个完整的基因序列，发现大多数物种中只有一个拷贝，而 Hesperinae 和 Heteropterinae（缀叶甲亚科）中有 2-3 个拷贝。所有基因都由两个外显子和一个内含子（39-45bp）组成，第二个外显子明显更长。与蝴蝶和蜉蝣目相比，飞蛾的基因中 GC 含量更高。FibH 的组成在物种间存在差异，蛾类和蝴蝶偏爱 Ala、Gly、Ser、Pro、Gln 和 Asn，而蜉蝣目 FibH 富含 Gly、Ser 和 Arg，Ala 较少。FibH 是蜉蝣目所特有的，而飞蛾类的 FibH 则以多 Ala（多丙氨酸）、多 Ser（多丝氨酸）和六肽 GAGSGA 为特征。系统发育分析表明，鳞翅目 FibH 是由蜉蝣目进化而来的，而缀叶甲亚科的 FibH 是由 Papilionoidea 进化而来的。本研究大大扩展了 FibH 的基因库，为人工丝的开发提供了基础。
