早酥梨及其红色芽变Ty1-copia反转录转座子逆转录酶的克隆与分析  

Cloning and comparative analysis of reverse transcriptase of Ty1-copiaretrotranspon in‘Zaosu'(Pyrus bretschneideri Rehd)pear and its red mutant

作　　者：周鹏[1] 仇宗浩[1] 翟锐[1] 梁东[1] 徐凌飞[1] 

机构地区：[1]西北农林科技大学园艺学院,农业部西北地区园艺作物生物学与种质创制重点实验室,陕西杨凌712100

出　　处：《西北农林科技大学学报（自然科学版）》2014年第5期162-170,182,共10页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(31171925);高校基本科研业务费项目(ZD2013005)

摘　　要：【目的】从早酥梨及其红色芽变基因组中克隆Ty1-copia反转录转座子逆转录酶序列,分析其特点和差异。【方法】根据Ty1-copia反转录转座子逆转录酶保守区域设计简并引物,建立并优化PCR扩增体系,回收、克隆、测序得到的目的基因序列。【结果】成功从早酥梨基因组和红色芽变材料中分别获得29,30条逆转录酶序列,序列大小均为260bp左右。生物信息学分析表明,与早酥梨相比,红色芽变的逆转录酶序列多发生终止子突变、缺失突变、替换突变。聚类分析可将所得序列分为7个家族,基于逆转录酶序列进行的不同物种进化树分析显示,第7家族序列与苹果和李具有很高的同源性,可能是反转录转座子横向传递的结果。【结论】早酥梨及其红色芽变Ty1-copia反转录转座子逆转录酶序列具有普遍性、异质性等特点,虽均已不具备转录活性,但红色芽变的逆转录酶序列突变程度更高。[Objective] The aim of this study was to clone and comparatively analyze the reverse transcriptase （RT） of Tyl coDia retrotranspon between ＇Zaosu＇ （Pyrus bretschneideri Rehd） pear and its red mutant. [Method] Using degenerate oligonucleotide primers corresponding to the conserved domains of the RT,a polymerase chain reaction（PCR）system was established and modified. The amplicons were recovered and cloned. Positive clones were selected, identified, sequenced and analyzed. [Result] 29 fragments with size of 260 bp were amplified from genome of ＇Zaosu＇ pear,and 30 from its red mutant. Compared with ＇Zaosu＇ pear, the amino acid sequences of RT in red mutant displayed more termination mutations, deletion mutations and substitution mutations. From dendogram analysis,all sequences could be classified into seven families. The amino cluster and alignment analyses of these sequences from other species showed that the seventh family had a close relationship with MalusX domestica and Prunus mume,indicating that they may have the same origin. [Conclusion] The RT of Tyl-copia retrotranspon in＇Zaosu＇ pear and its red mutant had high heterogeneity but no transcriptional activation. RT of red mutant mutated more severely.

关 键 词：梨 红色芽变 逆转录酶 进化分析 

分 类 号：S661.201[农业科学—果树学]