表达重组别藻蓝蛋白质粒在工程菌株中的遗传稳定性研究

Study on the Heredity Stability of a Recombinant Plasmid pMal-2X in Escherichia coli

将含有表达重组别藻蓝蛋白基因的重组质粒pMal-2X的工程菌株P1分别在含有Amp的LB固体培养基上采用划线法连续传代至100代,其生长速度(在LB培养基中)、菌落形态和抗生素抗性等方面与原始种子库无明显差异;取第10,20,50,100代提取质粒DNA经EcoRⅠ限制性内切酶酶切检查,酶切图谱没有改变。DNA测序未见apc基因变异。原代菌株与传代第10,20,50和100代菌株经诱导培养,其rAPC表达水平、菌体蛋白的SDS-PAGE图谱及重组蛋白的免疫原性均无明显差异。以上结果表明,重组质粒pMal-2X在工程菌株P1中具有良好的遗传稳定性。

The strain of TB1 from the original stock which harboring a recombinant plasmid pMal-2X including apc gene from cyanophyceae had been subcultured serialyto 100^th generation in Amp ^＋ plate. The growth characteristics and the morphology of the cultures did not show differences among the generations. The chromatogram of the plasraids in different generations digested by EcoRI restriction enzymes were same, as well as DNA sequences showed no difference among generations. In addition to that, origin strain and 10^th , 20^th , 50^th and 100^th generation strain had a similar rAPC expression level. The immunology activity of the rAPC and SDS-PAGE of the proteins expressed in different generations were also same. From the above results, it is indicated that recombinant stain P1 has a high hereditable stability.