Liang Linlin, Zhou Mingbing
The Nurturing Station for the State Key Laboratory of Subtropical Sil-viculture, Zhejiang A & F University, Lin'an 311300, Zhejiang, China.
Sheng Wu Gong Cheng Xue Bao. 2016 Apr 25;32(4):409-429. doi: 10.13345/j.cjb.150279.
Long terminal repeat (LTR) retrotransposons are mobile DNA sequences that ubiquitously exist in eukaryotic genomes. They replicate themselves in the genome by copy-paste mechanism with RNA as medium. In higher plants, many active LTR retrotransposons have been applied to analyze molecular marker technology, genetic tagging, insertion mutation and gene function. Here, we systematically review the characteristics of plant active LTR retrotransposons, including their structures, copy numbers and distributions. We further analyzed the gag (group-specific antigen) and pol (polymerase) sequence features of different plants active LTR retrotransposons and the distribution patterns of the cis-acting elements in LTR regions. The results show that autonomous active LTR retrotransposons must contain LTR regions and code Gag, Pr, Int, Rt, Rh proteins. Both LTR regions are highly homologous with each other and contain many cis-regulatory elements; RVT and RNase_H1_RT domain are essential for Rt and Rh protein respectively. These results provide the basis for subsequent identification of plant active LTR retrotransposons and their functional analysis.
长末端重复序列（LTR）逆转座子是广泛存在于真核生物基因组中的可移动DNA序列。它们以RNA为媒介，通过“复制-粘贴”机制在基因组中自我复制。在高等植物中，许多活跃的LTR逆转座子已被应用于分析分子标记技术、基因标签、插入突变和基因功能。在此，我们系统地综述了植物活跃LTR逆转座子的特征，包括它们的结构、拷贝数和分布。我们进一步分析了不同植物活跃LTR逆转座子的gag（群特异性抗原）和pol（聚合酶）序列特征以及LTR区域顺式作用元件的分布模式。结果表明，自主活跃的LTR逆转座子必须包含LTR区域并编码Gag、Pr、Int、Rt、Rh蛋白。两个LTR区域彼此高度同源，并包含许多顺式调控元件；RVT和RNase_H1_RT结构域分别对Rt和Rh蛋白至关重要。这些结果为后续鉴定植物活跃LTR逆转座子及其功能分析提供了依据。
