提高玉米产量是玉米育种的重要目标，而籽粒大小和粒重是禾谷类作物产量的重要构成因子。本研究根据水稻中已克隆的决定籽粒产量的主效基因OsGW2（RING型E3泛素连接酶）的序列信息，利用3’-RACE和RT-PCR技术从玉米基因组中分离出其直系同源基因，并对克隆的目的基因进行序列及组织表达特异性分析。结果表明，克隆得到的玉米同源基因编码区长为1287 bp，编码428 个氨基酸残基。Blastx功能分析发现该基因编码E3泛素连接酶类蛋白，该基因的编码序列与OsGW2的编码序列相似度高达83%，将其暂时命名为ZmGW2-1，且ZmGW2-1在雌穗中高度表达，表明该基因可能参与玉米雌穗的发育调控。该基因的克隆为进一步分析其功能奠定了基础。
Yield improvement is an important goal in maize breeding. Grain size and weight are two main yield components in cereal crops. In this study, 3’-RACE and RT-PCR were employed to isolate the maize orthologous gene according to the sequence information of the OsGW2 gene that was reported to be a major QTL controlling rice grain width and weight by encoding a RING-type protein with E3 ubiquitin ligase activity. The sequence and expression pattern of the maize target gene were analyzed. The results indicated that the coding sequence of the isolated maize orthologous gene has 1287 bp and encodes 428 amino acid residues. Blastx function analysis revealed that the maize orthologous gene encodes E3 ubiquitin protein enzyme. Compared to the complete coding sequence (CDS) of OsGW2, the homologous gene showed an 83% of similarity to OsGW2. We temporarily designated this homologous gene as ZmGW2-1. Meanwhile, ZmGW2-1 highly expressed in maize ears, indicating that it might play important roles in maize ear development. Isolation of ZmGW2-1 laid a good foundation for further study on its functions.