植物中微型反向重复转座元件(MITEs)在作物遗传研究中的应用进展

Miniature Inverted-repeat Transposable Elements (MITEs) in Plants Applied in Crop Genetics Research

MITEs(Miniature Inverted-repeat Transposable Elements),是最近发现的几乎在所有生物基因组中广泛分布的一类非自主型DNA转座元件,对基因组的结构和基因表达都有重要的影响。研究发现MTIEs的插入影响了许多重要农艺性状,在作物遗传研究中的应用价值也逐渐显现。为了更好地将这一转座元件利用于作物遗传研究和改良过程,文章概述了MITEs的发现及结构特点,对根据其特点进行预测的分析软件和数据库进行了总结;对MITEs在基因组中的分布特点进行了归纳,发现其在基因组中拷贝数众多,并多在近基因区分布;总结了MITEs同其来源的自主型转座子间的对应关系及转座活性的激活和在基因组中的扩增模式;MITEs对基因表达调控主要通过两种途径:即通过插入改变基因的结构从而影响基因表达和表观遗传水平的调控途径。同时对目前已有的MITEs在作物遗传分析,如开发分子标记,改良性状,构建突变体库等方面进行了总结归纳。

MITEs are novel non-autonomous DNA transposable elements and exist in almost all organisms.They play important roles in genome structure and gene expression.Research results demonstrate that MITEs affected many important agricultural characters,and their value in crop genetics research is also revealed.In order to apply MITEs to crop genetics research and improvement process well,we introduced the discovery and structural characteristics of MITEs,summarized software and database which predicted MITEs characteristics,and concluded the distribution of MITEs in genome.We found that many copies of MITEs appeared in genome,and distributed in recent genetic area.We also reviewed the corresponding relations between MITEs and its autonomous transposable element,the activation of transposition activity and the amplification mode in the genome.MITEs regulated gene expression through two different ways：MITEs insertion changing gene structure and epigenetic regulation.Finally,we summarized MITEs application in crop genetic analysis,for instance,molecular marker development,agricultural traits improvement,mutant pool construction etc.