瓠瓜Ty1-copia型逆转座子RT基因的分离与序列分析  

Cloning and Analysis of Reverse Transcriptase of Ty1-copia-like Retrotransposons in Bottle Gourd

作　　者：赵芹[1] 谢大森[1] 何晓明[1] 江彪[1] 罗少波[1] 彭庆务[1] 李明珠[1] 

机构地区：[1]广东省农业科学院蔬菜研究所,广东广州510640

出　　处：《热带作物学报》2014年第8期1577-1585,共9页Chinese Journal of Tropical Crops

基　　金：国家青年自然科学基金(No.31311643);广东省自然科学基金(No.10451064001006063);广州市珠江科技新星项目(No.2013086)

摘　　要：以3个瓠瓜栽培种为供试材料,利用Ty1-copia逆转座子逆转录酶保守序列设计简并引物,PCR扩增获得260bp左右序列条带,回收产物克隆至T载体进行测序,利用生物信息学软件分析获得的25条逆转录酶序列。结果表明,这些序列长度变化范围为218~267bp,经DNAStar软件比对同源性在26.1%~99.6%之间,存在高度异质性,主要表现为缺失突变,核苷酸序列聚类分析分为6个家族,家族1与家族3分别占总序列数的24.0%与36.0%。翻译成氨基酸序列后,分别有2条与11条序列发生移码与终止密码子突变。与已发表物种的相应序列构建系统发育进化树,发现瓠瓜Ty1-copia型逆转座子RT序列具有一定保守性,同时也与杨树、草莓、马铃薯等有很近的亲缘关系。本研究为后续利用逆转座子开发分子标记研究瓠瓜遗传变异及进化途径奠定基础。A fragment of 260 bp was amplified by PCR from genomic DNA of three bottle gourd materials using degenerate primers aimed at RT conserved motifs for investigating and understanding genetic relationship, characteristics and evolution of bottle gourd Tyl--copia-like retrotransposon families. The PCR products were cloned to pMD18-T vector and positive clones were identified and sequenced. Twenty fivedifferent sequences were obtained and analyzed by some bioinformatics softwares like. The result showed that length of these RT sequences varied from 218 to 267 bp, and sequence similarities ranged from 26.1% to 99.6% by DNAStar alignmet, and high heterogeneity showed by these sequenees were mainly characterized by deletion mutation. Six families were distinguished after alignment analyses of their nucleotide sequences, familyl and family2 were main members of bottle gourd retrotransposons and accounted for 24.0% and 36.0% respectively. Eleven and two sequences presented stop-codon and frame-shift mutations respectively after translated into amino acids. The amino acids cluster and alignment analyses of these sequences with other reverse transeriptase sequences in GenBank accessions showed that RT sequences of Tyl-copia-like retrotransposons in bottle gourd were conservative, and showed high homology with poplar, strawberry and potato. This work offers the basis for developing molecular markers based on retrotransposons to analyze the genetic variability and research the origin and evolution pathways of bottle gourd.

关 键 词：瓠瓜 Ty1-copia逆转座子 逆转录酶 克隆 序列分析 

分 类 号：S642.9[农业科学—蔬菜学] Q78[农业科学—园艺学]