中文摘要：

为了解龙眼miR171家族的进化特性及其功能，该研究以龙眼mRNA和miRNA数据库中获得的miR171家族7个前体序列(pre-miRNA)和9条成熟体序列为基础进行生物信息学预测和表达分析。mfold预测显示，pre-miR171家族成员均能形成典型二级结构，其最小折叠自由能（dG）介于-39.37~-55.13kal/mol，且家族成员中除pre-miR171-scaffold112和pre-miR171f-scaffold38外，其他成员包含的成熟序列与vvi-miR171a、ptc-miR171f以及ctr-miR171等成熟体完全匹配。NJ进化树分析发现，龙眼pre-miR171家族与柑橘、毛果杨具有较高相似性。psRNAtarget靶标预测显示，龙眼miR171家族的主要靶标为Scarecrow-like6，与其他植物的miR171靶标相同。实时荧光定量PCR分析表明，pre-miR171家族成员均在龙眼雄花中表达提高，而在果实中表达量降低。研究认为，龙眼miR171家族在进化过程中具有高度保守性，在龙眼生长发育过程中主要参与雄花形成。

英文摘要：

Seven precursors(pre-miRNAs)and seven mature sequence of the miR171family were obtained for analyzing the evolutionary characterization and its expression fromDimocarpus longanLour.(longan)mRNA and miRNA databases.The prediction results using mfold showed that the sequence of premiR171family members could form a typical secondary structure,and the minimum folding free energy(dG)in the range of-39.37to-55.13kal/mol.Other members of the mature sequence matched exactly with vvimiR171a,ptc-miR171f and ctr-miR171except pre-miR171-scaffold112and pre-miR171f-scaffold38.NJ phylogenetic tree analysis showed higher sequence homology with that fromCitrus reticulataandPopulus trichocarpa.Target prediction showed that the main target of longan miR171family wereScarecrowlike6,which was the same as miR171target of other plants.qPCR results indicated that premiR171family were strong expressed in the male flower and low in the fruit.It was suggested that the miR171family was highly conserved during the evolution and might play important roles in the development of male flowers in longan.