SELEX 筛选嗜水气单胞菌(Aeromonas hydrophila)适体方法的建立

嗜水气单胞菌是水产养殖中一种比较常见的致病病原菌。本研究以嗜水气单胞菌为研究对象,利用SELEX指数富集系统进化技术(Systematic Evolution of Ligands by Exponential Enrichment,SELEX),经过12轮的筛选,通过生物素-抗地高辛碱性磷酸酶显色系统检测DNA适配子与嗜水气单胞菌的亲和力,克隆、测序后,用DNAMAN软件分析其一级序列与二级结构。研究结果表明,通过12轮筛选后,亲和力由最初的0.32升到第9轮的0.72,亲和力提高了2.25倍。一级结构主要由GT组成,说明同源性适体有了一定程度的富集。二级结构模拟图以茎环状结构为主,说明这些茎环状结构可能是适体与靶分子进行结合作用的基础,也是其进一步形成三维空间结构的基础。

ESTABLISHMENT OF SELEX TECHNIQUE FOR SCREENING APTAMER FOR AEROMONAS HYDROPHILA

Aeromonas hydrophila is a relatively common disease-causing bacteria in aquaculture. The objective of this study is to obtain the aptamers to A. hydrophila by using SELEX and analysis its secondary structure. Take the A. hydrophila as the object, the study is started by the advanced technology named SELEX. After 12 rounds of selection and the affinity-testing by Biological element-anti-digoxin alkalinity phosphatase colored system, the aptamers were cloned, se-quenced and then analyzed its primary and secondary structure by the DNAMAN Software. The result showed that after 12 rounds of selection, the affinity raised 2.25 times from 0.32 in the third round to 0.72 in the ninth round, aptamers with primary structure homology had been enriched to some extent which are consisted of GT. The secondary structure con-sisted mainly of Stem-loop structure. This implicated that these Stem-loops were the basis for aptamers binding to target molecules as well as the basis for its further form the three-dimensional structure.