玉米MIR166基因家族的进化与功能研究

Molecular evolution and function of MIR166 gene family in maize

【目的】分析玉米MIR166基因家族的序列特征、分子进化及靶基因等,了解MIR166基因家族在玉米生长发育与逆境胁迫响应中的调控作用。【方法】运用生物信息学方法在mi RBase中搜索zma-MIR166基因家族的序列,用BLAST搜索工具进行基因定位;采用Clustal W2软件进行多序列比对,用MEGA 6.0构建zam-MIR166家族的系统发育进化树;利用ps RNATarget软件对zma-MIR166基因家族的靶基因进行预测。【结果】通过搜索,在玉米中找到14个zma-MIR166基因,并获得其对应的14个前体序列及由其产生的26个成熟mi RNA序列。zma-MIR166基因家族在产生成熟mi RNA的位置高度保守,其他位置则保守性减弱。基因定位结果发现,zma-MIR166基因家族的14个成员分布在染色体1、3、4、5、6、7等6条染色体上,其中以染色体1上zma-MIR166基因最多,共有5个。进化分析结果表明,14个zma-MIR166基因家族成员分别处于3个进化分支,而同处于一条染色体上的成员的亲缘关系较远。对zam-MIR166基因家族的靶基因进行预测,发现zma-MIR166基因家族靶基因功能涉及发育调控蛋白家族、胁迫相关蛋白、光系统I作用中心亚基、转座子插入位点等。【结论】zam-MIR166基因家族序列保守性较高,具有明显的家族特征与相似的功能,在玉米生长发育和胁迫响应等生物过程中发挥广泛而重要的调控作用。

【Objective】The comprehensive analysis of sequence characters, molecular evolution, and target gene prediction of MIR166 gene family in maize were conducted in order to lay the foundation for understanding their roles in reg-ulating the development and adversity stress response. 【Method】The sequences of zma-MIR166 gene family were searched in mi RBase by using bioinformatics method. Gene mapping was performed using BLAST tool. Then Clustal W2 was used for multiple sequence alignment and MEGA6.0 was used for constructing phylogenetic tree of zma-MIR166 gene family. Furthermore, target genes of zma-MIR166 gene family were predicted by ps RNATarget tool. 【Result】A total of 14 zma-MIR166 gene were found in mi Rbase, and their 14 precursor sequences and 26 mature mi RNA sequences of zma-MIR166 gene family were obtained. Multiple sequence alignment of precursor sequences showed that, the region generating mature mi RNA was higher conservative. Gene mapping results suggested that, the 14 genes were distributed on 6 chromosomes viz., Chr1 and Chr3-Chr7. Of which, Chr1 presented the most zma-MIR166 genes（5 genes）. Phylogenetic tree results revealed that, zma-MIR166 gene family was divided into 3 groups, and the zma-MIR166 genes on the same chromosome had a farther genetic relationship. Target gene prediction of zma-MIR166 family revealed that, their targets were involved to development regulating factors, stress related proteins, subunit of photosystem I reaction centrel, transposon insertion site and so on. 【Conclusion】zma-MIR166 gene family was high conserved and characterized by obvious family charactericstic and similar function. They played important regulating roles in development and stress response of maize.