杨梅肌动蛋白基因MrActin1的克隆及表达分析

扩增杨梅嫩叶中肌动蛋白基因(MrActin1)全长编码区cDNA序列，并评价MrActin1的进化地位，同时分析MrActin1的表达模式。利用RT-PCR扩增MrActin1全长编码区cDNA序列。用生物信息学手段分析预测MrActin1的理化性质和同源性，用临接法构建其的系统发生树。通过Northern blot分析MrActin1在不同组织部位的表达。该基因cDNA序列（GenBank登录号AB 650589）全长1137 bp，编码了1个由377个氨基酸残基组成的蛋白质，所得序列与GenBank中注册的其他植物Actin氨基酸序列的相似性均在88%以上，根据高等植物Actin相似性构建了进化树，表明MrActin1与陆地棉、圆叶锦葵Actin之间的亲缘关系最为密切，在进化中分化时间最为接近。Northern blot分析表明，MrActin1在杨梅的花、叶、枝条和果组织中恒定表达。首次获得了杨梅MrActin1 cDNA全长序列。

Cloning and Expression Analysis of MrActin1 Gene from Myrica rubra

The aims were to clone a full-length cDNA （MrActin1） of actin from Myrica rubra leaves, and evaluate its evolution status and analyze the expression model of MrActin1. A full-length cDNA of actin was obtained using RT-PCR techniques. The physicochemical properties and homology analyzed by bioinformatics methods. The phylogenetic tree of actin family was constructed by neighbor-joining. The expression model of MrActin1 investigated in various organs of Myrical rubra. The full length of MrActin1 was 1137 bp （GenBank accession No. AB 650589）, encoding a protein of 377 amino acids. Homologous alignment showed that it shared over 88% nucleotide sequence similarity. The phylogenetic tree reconstructed on the base of amino acid sequences suggested that the relationship of actin between Myrica rubra and Gossypium hirsutum, Malva pusilla was most intimate and they might have the same differential time in evolution. The analysis by Northern blot showed that MrActin1 was constantly expressed in various organs of Myrical rubra such as flowers, leaves, branches, fruits. The full-length cDNA sequence of MrActin1 was firstly obtained.