野桑蚕、家蚕LSP基因5'侧翼区的克隆与序列分析

根据已报道的家蚕朝日×东海的幼虫血清蛋白LSP基因序列设计1对引物,以野桑蚕、家蚕苏·菊×明·虎的基因组DNA为模板,分别克隆了野桑蚕、家蚕苏·菊×明·虎的LSP,基因5’侧翼区,约1.9kb,并进行了序列测定与分析。结果表明:克隆的野桑蚕、家蚕苏·菊×明·虎的LSP基因5’侧翼区涵盖了第一内含子、第一外显子、启动子区及其5’上游区;野桑蚕LSP基因5’侧翼区与朝日×东海LSP,基因5’侧翼区的同源性达96.4％,其中第一内含子、第一外显子的同源性分别为91.6％,100％;家蚕苏·菊×明·虎的LSP基因5’侧翼区与朝日×东海LSP基因5’侧翼区的同源性达98.9％,其中第一内含子、第一外显子的同源性都为100％,核心启动子区具有典型的TATA盒,还有数种昆虫脂肪体内组织特异性表达基因的共有序列和推定的激素响应元件等功能元件;野桑蚕的LSP基因启动子的5’上游区(-304～598bp)与J139家蚕丝素轻链基因第一内含子区域(7639～7933bp)的同源性达90.6％,-913～-1383bp为失活的部分水手转座子元件。

Cloning and Sequencing of the 5'-flanking Region of Larval Serum Protein(LSP) Genes From Bombyx mandarina and Bombyx mori

According to reported sequence of Bombyx mod Larval Serum Protein Gene (BmLSP) from the variety of Tokai x Asahi,one pair primer were designed. The 5'-flanking regions, about 1.9 kb, of Larval Serum Protein gene, Bombyx mandarina, BmandLSP5' FR and Bombyx mori, BmLSP5' FR( Su. Ju x Ming . Hu) were attained by PCR and subcloned into pSK plasmid.The sequencing of them indicated that both BmandLSPS'FR and BmLSP5'FR(Su.Ju x Ming Hu) are constituted by the first intron, the first exon,the central promoter and its 5'-upstream region.The BmandLSP5' FR,the first intron and exon of the BmandLSP5'FR are 96.4%, 91. 6% and 100% identical to the counterparts of BmLSP,while the BmLSPS'FR (Su.Ju x Ming.Hu),the first intron and exon of the BmLSP5'FR(Su.Ju x Ming.Hu) are 98.9% ,100% and 100% identical to the counterparts of BmLSP, respectively. The typical TATA box,the sequence commonly found in insect genes that were specifically transcribed in fat body and the deduced ecdysone-responsive element were found in both of them. There existed the homologous region( - 304--598 bp), with 90.6% similarities to that of the first intron of the J139 fibrion light-chain gene, and part of inactive mariner-like element ( -913 ~ - 1 383 bp)in the BmandLSP5'FR.