柞蚕肌球蛋白轻链1基因(MLC-1)的序列特征及表达谱与系统进化分析

Sequence Feature,Expression Pattern and Phylogenetic Analysis of Myosin Light Chain 1 Gene( MLC-1 ) from Chinese Oak Silkworm,Antheraea pernyi

从柞蚕蛹全长cDNA文库中分离和鉴定了柞蚕肌球蛋白轻链1(myosin light chain 1,MLC-1)基因。柞蚕MLC-1基因全长863 bp,包含一个453 bp的开放阅读框,编码150个氨基酸,预测蛋白质的分子质量为16.75 kD,等电点为4.62。柞蚕MLC-1基因在4个发育阶段(卵、幼虫、蛹、成虫)和幼虫的10种组织(血液、脂肪体、中肠、丝腺、体壁、马氏管、精巢、卵巢、大脑和肌肉)中均有表达,表明该基因在柞蚕生长发育过程中起着重要作用。柞蚕MLC-1与已知鳞翅目昆虫MLC-1的序列相似度为88%～98%,与其它昆虫MLC-1的序列相似度为60%～74%,表明MLC-1在昆虫的进化过程中高度保守。利用MLC-1蛋白质序列构建的系统进化树中,无脊椎动物和脊椎动物明显地聚成2个类群,且鳞翅目、膜翅目、半翅目、双翅目等昆虫的聚类也与传统形态学分类相一致。

Myosin light chain 1 （MLC-1） gene was isolated and characterized from full-length cDNA library of Antheraea pernyi pupa. The full-length A. pernyi MLC-1 gene is 863 bp long and contains a 453 bp open reading frame encoding a150 amino acid protein with a predicted molecular weight of 16.75 kD and pl of 4.62. MLC-1 gene was transcribed at four developmental stages （egg, larva, pupa, and moth） and in all ten tissues tested （blood, fat body, mid- gut, silk gland, integument, Malpighian tubule, sperma- ry, ovary, brain, and muscle）, indicating that MLC-1 plays an important role during growth and development of A. pernyi. A. pemyi MLC-1 shares 88% to 98% sequence identity with MLC-1 from known Lepidopteran insects, while it has a sequence identity ranging from 60% to 74%with that of other insects, indicating that MLC-1 is highly conserved in the process of insect evolution. The phylogenetic tree constructed with MLC-1 protein sequences showed that invertebrates and vertebrates formed two distinct groups. Clustering of insects from Lepidoptera, Hymenoptera, Hemiptera and Diptera was consistent with traditional morphologic classification.