摘要
In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuA gene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence. The functional detection of every mutant was performed at the level of culture medium and cell experiment. The gene expression profiles of the mutants and the wild-type strains under iron- enriched and iron-limited conditions were analyzed by the SD51197 whole genomic microarray. The results showed that all the mutants grew obviously less well than the wild-type strains in L broth appending iron chelator DIP. The addition of iron to the cultures can stimulate the growth of mutants back to wild-type levels. In either the experiments on the ability of intracellular multiplication or the cell-to-cell spread in HeLa and U937 cell lines, mutants showed no obvious change in virulence compared with the parental strain SD51197. However when DIP was added to the cultured HeLa cells, the ability of intracellular multiplication of MTS-1, MTS-2, MTS has reduced about 23.4%, 25.2%, 43.6% respectively. The analysis of expression profiles under the iron-limited condition showed that the mutants were more sensitive for the changes of iron deficiency than the wild-type strains, many genes have been altered. Up-regulated genes mainly involved genes of transcription, coenzyme metabolism, amino acid transport and metabolism, and unknown functional genes, while down-regulated genes mainly involved genes of energy and carbohydrate metabolism and unknown function genes; the expression levels of known iron-transport associated genes generally showed up-regulated. The results demonstrated that iron-transport associated genes IroN, ShuA were likely to have some effects on the virulence and growth of S. dysenteriae.
In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuAgene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence.The functional detection of every mutant was performed at the level of culturemedium and cellexperiment. The gene expression profiles of the mutants and the wild-type strains underiron-enriched and iron-limited conditions were analyzed by the SD51197 whole genomic microarray. Theresults showed that all the mutants grew obviously less well than the wild-type strains in L brothappending iron chelator DIP. The addition of iron to the cultures can stimulate the growth ofmutants back to wild-type levels. In either the experiments on the ability of intracellularmultiplication orthe cell-to-cell spread in HeLa and U937 cell lines, mutants showed no obviouschange in virulence compared with the parental strain SD51197. However when DIP was added to thecultured HeLa cells, the ability of intracellular multiplication of MTS-1, MTS-2, MTS has reducedabout 23.4%, 25.2%, 43.6% respectively. The analysis of expression profiles under the iron-limitedcondition showed that the mutants were more sensitive for the changes of iron deficiency than thewild-type strains, many genes have been altered. Up-regulated genes mainly involved genes oftranscription, coenzyme metabolism, amino acid transport and metabolism, and unknown functionalgenes, while down-regulated genes mainly involved genes of energy and carbohydrate metabolism andunknown function genes; the expression levels of known iron-transport associated genes generallyshowed up-regulated. The results demonstrated that iron-transport associated genes IroN, ShuA werelikely to have some effects on the virulence and growth of S.dysenteriae.
作者
BIN Wen, LIU Moqing, PENG Junping, SUN Lilian, XU Xingye, ZHANG Jinghai& JIN Qi Shengyang Pharmaceutical University, School of Pharmaceutical Engineering, Shengyang 110016, China
State Key Laboratory for Molecular Virology and Genetic Engineering, Beijing 100176, China
