美洲水貂DQA基因全长cDNA克隆及其生物信息学分析

Cloning and Bioinformatics of Full-length cDNA of DQA Gene in Neovison vison

参考NCBI GenBank中上传的雪貂、海獭DQA基因序列设计出RT-PCR扩增引物,克隆了美洲水貂DQA基因全长cDNA序列;利用生物信息学软件构建了DQA基因系统进化树,预测了DQA蛋白结构与功能。结果表明:DQA基因全长cDNA序列大小为1 147 bp, ORF序列为768 bp,编码255个氨基酸,存在23个氨基酸的信号肽序列;DQA蛋白第236位氨基酸疏水性最强,53位氨基酸亲水性最强,218-240氨基酸可能为跨膜区域;蛋白质二级结构存在3个α-螺旋区和14个β-折叠区,处于无规则卷曲状态。获得了一个DQA蛋白三级结构模型,覆盖范围为25-208氨基酸;系统进化树表明,美洲水貂与欧洲雪貂亲缘关系最近,与家马关系最远。该研究结果为进一步阐明水貂DQA基因和蛋白的结构与功能提供了一定数据基础。

Specific primers for RT-PCR were designed based on DNA sequences of DQA gene in ferrets and sea otters from GenBank and full-length sequences of DQA gene for Neovison vison were obtained. Phylogenetic tree of DQA gene was constructed and its bioinformatics was studied by related bioinformatics software. The results showed that the full-length cDNA of DQA gene was 1 147 bp included 768 bp ORF sequence, which encoded 255 amino acids and had a signal peptide sequence with 23 amino acid. The hydrophobic was the most at 236 position amino acid and the hydrophilic was the most at 53 position amino acid. The transmembrane domains might locate between 218-240 amino acids;The prediction of secondary structure revealed that there were 3 α-helical regions and 14 β-fold regions, which were random coil. A tertiary structure model was obtained, covering a range of 25-208 amino acids. The phylogenetic tree indicated that Neovison vison had the closest relationship with European ferrets, while farthest with domestic horse. This study provides a theoretical basis for the further research of DQA gene and protein in mink.