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为了解植物miR159家族成员的进化特性及其在不同组织部位的表达规律,以龙眼miR159家族为例对miRNA家族进行探讨.通过龙眼miR159家族前体与成熟体序列比对、前体二级结构预测、系统发育进化树的构建、靶基因预测及实时荧光定量等手段,对龙眼miR159基因家族进行研究.结果显示:龙眼miR159家族存在7个前体成员和6个成熟体成员,序列比对发现5个成熟体可以高度定位于7个前体序列中一个共有的、约20个碱基的保守区域,推测miR159成熟体主要来源于该区域;进一步分析发现6个成熟体序列中仅2个可定位于pre-MIR159中.mfold预测结果显示miR159家族7个前体的最小折叠自由能在-56.54--92.53 kal/mol之间,均能自发形成典型、稳定的茎环二级结构.系统发育进化树显示龙眼miR159家族前体与成熟体成员均具有保守性与多样性.靶基因预测发现龙眼miR159家族所有成员共预测出14个不同靶标,其中3个成员也可以作用于同一靶标.实时荧光定量PCR显示,龙眼pre-MIR159家族成员间在不同组织部位表达量差异显著,但表达趋势却几乎一致,其中花器官中表达量最高,提示了dlo-miR159在生殖器官形成过程中具有重要的作用,尤其是在雄花中作用显著.本研究表明龙眼miR159家族在进化过程中形成了保守性与多样性并存的进化特性,并且可能在花器官形成过程中发挥了重要的作用.
In order to understand the evolutionary characteristics of plant miR159 family members and their expression patterns in different tissues and tissues, the miR159 family of longan was used as an example to study the miRNA family.Sequence prediction of precursor secondary structure , Phylogenetic tree construction, target gene prediction and real-time fluorescence quantitative analysis of the longan miR159 gene family.The results showed that there are 7 precursor members and 6 mature members of longan miR159 family, the sequence alignment found 5 One mature body can be highly located in a common conserved region of about 20 bases among the seven precursor sequences. It is speculated that the mature body of miR159 is mainly derived from this region. Only two of the six mature sequences can be located In pre-MIR159, mfold prediction showed that the minimum folding free energy of miR159 family of seven precursors could spontaneously form secondary stable stalk loop secondary structures between -56.54 and 92.53 kal / mol. The tree shows that the longan miR159 family of precursors and mature body members are conservative and diverse target gene prediction found that all members of the longan miR159 family predicted a total of 14 different targets , Of which 3 members can also act on the same target.RT-PCR showed that the expression of pre-MIR159 members in longan differed significantly in different tissues, but the expression trends were almost the same, among which the highest expression was found in floral organs Dlo-miR159 plays an important role in the process of genitalia formation, especially in male flowers.The present study indicated that the evolutionary characteristics of conserved and diverse coexistence of miR159 in the longan were evolved, The formation process has played an important role.