Guo Da-Long, Hou Xiao-Gai, Jia Tian
College of Forestry, Henan University of Science and Technology , Luoyang , Henan , P. R. China.
College of Agriculture, Henan University of Science and Technology , Luoyang , Henan , P. R. China.
Biotechnol Biotechnol Equip. 2014 May 4;28(3):438-446. doi: 10.1080/13102818.2014.925312.
Tree peony is an important horticultural plant worldwide of great ornamental and medicinal value. Long terminal repeat retrotransposons (LTR-retrotransposons) are the major components of most plant genomes and can substantially impact the genome in many ways. It is therefore crucial to understand their sequence characteristics, genetic distribution and transcriptional activity; however, no information about them is available in tree peony. Ty1--like reverse transcriptase sequences were amplified from tree peony genomic DNA by polymerase chain reaction (PCR) with degenerate oligonucleotide primers corresponding to highly conserved domains of the Ty1--like retrotransposons in this study. PCR fragments of roughly 270 bp were isolated and cloned, and 33 sequences were obtained. According to alignment and phylogenetic analysis, all sequences were divided into six families. The observed difference in the degree of nucleotide sequence similarity is an indication for high level of sequence heterogeneity among these clones. Most of these sequences have a frame shift, a stop codon, or both. Dot-blot analysis revealed distribution of these sequences in all the studied tree peony species. However, different hybridization signals were detected among them, which is in agreement with previous systematics studies. Reverse transcriptase PCR (RT-PCR) indicated that Ty1- retrotransposons in tree peony were transcriptionally inactive. The results provide basic genetic and evolutionary information of tree peony genome, and will provide valuable information for the further utilization of retrotransposons in tree peony.
牡丹是一种在世界范围内具有重要观赏和药用价值的园艺植物。长末端重复逆转座子（LTR-逆转座子）是大多数植物基因组的主要组成部分，能够在许多方面对基因组产生重大影响。因此，了解它们的序列特征、遗传分布和转录活性至关重要；然而，牡丹中关于它们的信息尚无报道。在本研究中，通过聚合酶链反应（PCR），使用与Ty1类逆转座子高度保守结构域相对应的简并寡核苷酸引物，从牡丹基因组DNA中扩增出Ty1类逆转录酶序列。分离并克隆了约270 bp的PCR片段，获得了33个序列。根据比对和系统发育分析，所有序列被分为六个家族。观察到的核苷酸序列相似性程度的差异表明这些克隆之间存在高度的序列异质性。这些序列中的大多数都有移码、终止密码子或两者皆有。斑点杂交分析揭示了这些序列在所有研究的牡丹品种中的分布。然而，在它们之间检测到了不同的杂交信号，这与先前的系统学研究结果一致。逆转录酶PCR（RT-PCR）表明牡丹中的Ty1-逆转座子转录无活性。这些结果提供了牡丹基因组的基本遗传和进化信息，并将为逆转座子在牡丹中的进一步利用提供有价值的信息。
