关键词: 甲基营养菌, 荧光报告基因, 相对荧光强度

Abstract: Fluorescent protein has been a commonly used molecular marker in genetic engineering over the recent years,detailed interpretation of the expressions of different fluorescent protein genes in Methylobacterium extorquens is for identifying the most suitable fluorescent reporter gene. Genes of 5 fluorescent proteins,the frequently-used green fluorescent protein eGFP,red fluorescent protein mCherry,and yellow fluorescent protein YFP,as well as green fluorescent protein wGFP and red fluorescent protein RFP from other sources were cloned,the corresponding expression vectors were constructed,and their expressions in M. extorquens AM1 were achieved. Fluorescence protein expression in the transformants was identified via fluorescence imaging observation and SDS-PAGE protein gel electrophoresis. Furthermore,bacteria-growth curve,total fluorescence amount and relative fluorescence intensity were detected in all transformants to illustrate the fluorescence stability and expression intensity. As results,all target fluorescent proteins in the transformants were detected,while RFP expressed in a trace and no imaging was observed,and YFP presented the most stable and the highest relative fluorescence intensity as the 1.6 times of common eGFP,and 3.4 times of mCherry. In sum,YFP is the optimal fluorescent protein for M. extorquens AM1.

Key words: Methylobacterium extorquens, fluorescence reporter gene, relative fluorescence intensity