Escherichia Coli YdeE Gene Mutation Mediates Environment Adaptation And Its Mechanism

The adaptive effects of mutations may depend on the living environment in which they occur,thereby affecting the future opportunities of the evolving population,especially stable mutations in the population may change subsequent mutations of the selective advantage.In this paper,the 2000 generation MG1655 cell population(NO.14 strain)cultured under the stress of nutrient-poor(ABTG medium)and low temperature(30?)is chose be the research object,focusing on exploring the environmental adaptation and its mechanism of Escherichia coli mediated by ydeE gene mutationGenomic and transcriptome analysis of Escherichia coli that has been adapted to a nutrient-poor low-temperature environment(No.14 strain)revealed that this strain has 1 SNP in the ydeE gene;and 43 In Dels,which are mainly distributed in ion transport,ABC transport,and ribosome function Related genes.Transcriptome GO enrichment analysis showed that there were a total of 45 genes in the nutritional metabolism pathway,including 11 up-regulated genes and 34 down-regulated genes;KEGG enrichment analysis showed that the differentially expressed genes were mainly in(1)amino acid metabolism,(2)nitrogen Metabolism and(3)ABC transport and other pathways.Further analysis showed that the ydeE mutant grown faster with larger size and early initiation of replication in the poor-nutrient low temperature growth condition.In order to further explore the mechanism of the ydeE gene and its mutation in the environmental adaptation of Escherichia coli,we constructed the ydeE-simulated-mutation strain JCY2,the ydeE deletion mutant JCY1,JCY1 with overexpression of the ydeE-simulated-mutation gene,named JCY4,and JCY1 with overexpression of the wildtype ydeE gene,JCY3.The cell cycle parameter measurement showed that:(1)the ydeE-simulated mutant grew with slower growth rate and smaller size;(2)overexpression of the ydeE-simulated-mutation gene triggered an early initiation of replication;(3)expressions of the araA,pepA,pepB,pepD and pepN gene in the ydeE-simulated mutant was significantly increased.In summary,the point mutation of ydeE can change expression of genes associated with the amino acid metabolism and ABC transport pathways,and the changes subsequently leads to adaptation of Escherichia coli cells to the poor-nutrient low temperature environment.