PDF(Pubmed)
Abstract：
The FibH 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 FibH gene sequences from Lepidoptera (71 moths, 24 butterflies) and 13 Trichoptera, revealing single-copy FibH in most species, with 2-3 copies in Hesperinae and Heteropterinae (subfamily of skippers). All FibH 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 FibH 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.
摘要：
FibH基因,对昆虫的丝绸纺纱至关重要，编码一种显着影响蚕丝纤维力学的蛋白质。由于其大尺寸和重复序列，有限的已知昆虫FibH序列阻碍了全面的理解。这里,我们分析了来自鳞翅目的114个完整的FibH基因序列（71蛾，24只蝴蝶）和13只毛翅目，揭示大多数物种的单一拷贝FibH，在Hesperinae和Heteropterinae（船长亚科）中具有2-3个拷贝。所有FibH基因的结构有两个外显子和一个内含子（39-45bp），第二个外显子明显更长。与蝴蝶和毛翅目相比，飞蛾在FibH中的GC含量更高。FibH成分因物种而异，飞蛾和蝴蝶喜欢阿拉，Gly,Ser,Pro,Gln,Asn,虽然毛翅目纤维富含Gly，Ser,还有Arg,还有较少的Ala.毛翅目纤维的独特之处在于Tyr,Val,Arg,Trp,而鳞翅目FibH标记为聚Ala（聚丙氨酸），polyser（polyserer），和六肽GAGSGA。系统发育分析表明，鳞翅目由毛翅目进化而来，船长FibH是从Papilionoidea进化而来的。这项研究大大扩展了FibH曲目，为人造丝的发展奠定了基础。
