家蚕芳基贮藏蛋白新成员BmSP3的基因克隆与表达分析  

Molecular Cloning and Expression Profile of a Novel Bombyx mori Arylphorin Member BmSP3

作　　者：李建伟[1] 王阿蓉[1] 李懿[1] 黎治浪 龚竞[1] 侯勇[1] 夏庆友[1] 

机构地区：[1]家蚕基因组生物学国家重点实验室西南大学生物技术学院,重庆400716

出　　处：《蚕业科学》2014年第4期613-619,共7页ACTA SERICOLOGICA SINICA

基　　金：国家重点基础研究计划“973”项目(No.2012CB114600);国家自然科学基金项目(No.31201853,31101768);西南大学博士基金项目(No.104310-20700903)

摘　　要：贮藏蛋白在家蚕幼虫5龄盛食期的脂肪体中高量表达,为家蚕变态发育提供重要的营养物质,已报道的家蚕贮藏蛋白成员包括BmSP1和BmSP2,其中BmSP2为富含芳香族氨基酸的芳基贮藏蛋白(arylphorin)。从家蚕5龄幼虫脂肪体中鉴定并克隆了一个新的芳基贮藏蛋白基因,命名为BmSP3(GenBank登录号:JQ043182)。该基因ORF全长2 091 bp,编码697个氨基酸,BmSP3与BmSP2具有较高的序列相似性。半定量RT-PCR和实时荧光定量PCR检测显示:BmSP3在家蚕5龄第3天幼虫的脂肪体、表皮、生殖腺和头部中均有表达,其中在脂肪体中的表达水平最高,并且同一组织中雌蚕的表达水平明显高于雄蚕;BmSP3在4龄末幼虫的脂肪体中就有表达,5龄中期表达水平开始明显增加,到上蔟前达到最高峰,之后急剧下降。Western blot检测显示:BmSP3在家蚕幼虫阶段主要存在于血淋巴中,化蛹时转运至脂肪体中,在羽化前逐渐被降解。BmSP3基因的转录及蛋白质合成、转运特征与BmSP2极为相似。Storage proteins are expressed highly in fat body of silkworm（Bombyx mori） larvae at the voracious stage of the 5th instar,which provide vital nutrients for silkworm metamorphic development.Storage proteins of silkworm were reported to have two members,BmSP1 and BmSP2.BmSP2 belongs to aryphorin rich in aromatic amino acid.A novel gene encoding arylphorin storage protein named BmSP3（GenBank accession No.JQ043182） was cloned and identified from fat body of the 5th instar silkworm larvae.The open reading frame of BmSP3 was 2 091 bp and encoded a protein of 697 amino acids,which had high similarity to the reported Bombyx mori arylphorin storage protein BmSP2.Gene expression investigated by semi-quantitative RT-PCR and qRT-PCR revealed that BmSP3 was expressed in fat body,epidemis,gonad and head of silkworm larvae,among which the highest expression occurred in fat body.The expression level in a specific tissue of female larvae was higher than that of male ones.Expression of BmSP3 was detectable in larval fat body at late stage of the 4th instar,increased remarkably from middle stage of the 5th instar,reached a peak before spinning cocoons,and then declined sharply.Western blotting detection indicated that BmSP3 mainly exist in hemolymph,transport into fat body during pupation,and disappear before eclosion.The characteristics of transcription,protein synthesis and transport of BmSP3 were similar to those of BmSP2.

关 键 词：家蚕 芳基贮藏蛋白 BmSP3蛋白 基因克隆 表达特征 

分 类 号：S881.2[农业科学—特种经济动物饲养] Q785[农业科学—畜牧兽医]