两种土著食细菌线虫取食相关基因的克隆及序列分析  

Cloning and sequence analysis of feeding related genes of two native bacterial-feeding nematodes

作　　者：李孟迪 李滕 虞丽[1] 刘婷[1] 肖花美[2] 李辉信[1] LI Mengdi;LI Teng;YU Li;LIU Ting;XIAO Huamei;LI Huixin(College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China;Key Laboratory of Crop Growth and Development Regulation of Jiangxi Province,College of Life Sciences and Resource Environment,Yichun University,Yichun 336000,China)

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]宜春学院生命科学与资源环境学院,江西省作物生长发育调控重点实验室,宜春336000

出　　处：《应用与环境生物学报》2022年第1期160-166,共7页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(41877057);中央高校基本科研业务费专项资金(KJQN202015)资助。

摘　　要：探究土壤食细菌线虫取食偏好的分子机制是揭示其如何发挥生态学功能的关键,而明确取食相关基因的序列和结构对于探究其取食偏好的分子机制至关重要.采用RT-PCR和RACE方法从两种土著线虫(中杆属线虫Mesorhabditis sp.NJ和拟丽突属线虫Acrobeloides sp.NJ)中各克隆到5条取食相关基因的全长cDNA序列,分别命名为Msp-egl-4、Msp-gcy-28、Msp-odr-3、Msp-tax-2、Msp-tax-4和Asp-egl-4、Asp-gcy-28、Asp-odr-3、Asp-tax-2、Asp-tax-4.应用生物信息学方法对这10条基因进行序列及理化特性分析,并对其编码蛋白的保守结构域、跨膜结构域、二级结构、三级结构等进行预测.结果显示10条基因全长912-3699 bp不等,分别编码304-1233个氨基酸.将氨基酸序列与秀丽隐杆线虫Caenorhabditis elegans比对发现,线虫两两之间相同功能基因的相似性比例在50%以上.这10个基因都具有特定的保守结构域及重要功能位点,编码蛋白的二级结构以α-螺旋为主.三级结构预测表明:两种土著线虫中,EGL-4、TAX-2和TAX-4分别由同一模版预测得到,说明其序列结构的保守性,GCY-28和ODR-3分别由不同的模版预测得到,暗示其序列结构在进化过程中出现了分化.本研究结果获得了两种土著食细菌线虫取食偏好相关基因的序列和结构,并预测了相关保守的结构域和功能位点,可为后续探究食细菌线虫取食相关基因的生物学功能和取食偏好的分子机制提供理论基础.It is very important to identify the sequence and structure of feeding related genes for exploring the molecular mechanism of feeding preferences in bacterial-feeding nematodes.In this study,five full-length cDNA sequences of feeding-related functional genes were cloned from two native nematodes(Mesorhabditis sp.NJ and Acrobeloides sp.NJ)by RT-PCR and RACE methods.They were named as Msp-egl-4,Msp-gcy-28,Mspodr-3,Msp-tax-2,Msp-tax-4 and Asp-egl-4,Asp-gcy-28,Asp-odr-3,Asp-tax-2 and Asp-tax-4,respectively.The sequences and physicochemical properties of these 10 genes were analyzed using bioinformatics methods,and the conserved and transmembrane domains and secondary and tertiary structures of the encoded proteins were predicted.The results showed that the total length of the 10 genes varied from 912-3699 bp,encoding 304-1233 amino acids respectively.These amino acid sequences were compared with the sequences of the homologous proteins of Caenorhabditis elegans.It was found that the similarity of the same functional genes between the nematodes was at least 50%.All 10 genes have specific conserved domains and many important functional sites.The secondary structures of the proteins were dominated byα-helix.The predicted results of tertiary structure showed that EGL-4,TAX-2,and TAX-4 of the two native nematodes were predicted by the same template,indicating that their sequence structures were conservative.However,GCY-28 and ODR-3 were predicted by different templates,suggesting that their sequences and structures were differentiated in the evolutionary process.The results of this study established the sequences and protein structures of the feedingrelated genes of two native nematodes and predicted some conserved domains and functional sites,laying a theoretical foundation for the subsequent exploration of the biological function and the molecular mechanism of the feeding preferences of bacterial-feeding nematodes.

关 键 词：土著食细菌线虫 取食基因 基因克隆 序列分析 蛋白功能分析 

分 类 号：S154.386[农业科学—土壤学]