motB 和 fliC 基因在大肠杆菌运动中的作用

周身含有鞭毛的细菌可通过鞭毛马达带动鞭毛转动,为自身运动提供动力。文章以大肠杆菌为模式生物,通过CRISPR-Cas9基因编辑技术对大肠杆菌基因组进行改造,分别构建motB和fliC基因缺失的大肠杆菌菌株;利用明场显微技术研究单个鞭毛马达的转动,利用暗场显微技术研究单个细菌的游动,利用软琼脂平板研究细菌的群体游动。结果表明:motB和fliC基因缺失的大肠杆菌失去了马达转动和细胞运动的能力;通过质粒pJY7和pKAF131分别回补motB和fliC基因,恢复了大肠杆菌的运动能力,进一步明确了motB和fliC基因在大肠杆菌运动中的作用。

Peritrichous bacteria can provide motivation for own motility by employing flagellar motor to turn the flagella. In this paper, Escherichia coli was used as model organism, and the Escherichia coli genome was modified by CRISPR-Cas9 gene editing technology to construct the Escherichia coli strains without motB and fliC, respectively. The rotation of single flagellar motor was studied by bright field microscopy; the individual bacterial swimming motility was studied by dark field microscopy; the swimming motility of bacterial population was studied by using soft agar plates. The results showed that the strains of Escherichia coli without motB and fliC lost the ability of motor rotation and bacterial motility. The motility of Escherichia coli was restored when plasmids pJY7 expressing motB and pKAF131 expressing fliC were transformed to the cells. The results suggested the role of motB and fliC in the motility of Escherichia coli.