title: ﻿Differential expression of dnaA and dosR genes among members of the Mycobacterium tuberculosis complex under oxic and hypoxic conditions.
abstract: Major differences regarding the pathology and host immune response of the Beijing and Canettii genotypes of Mycobacterium tuberculosis have been reported; however, studies on the genetic expression of these genotypes during in vitro dormancy are scarce. This study examined the expression of five cell-cycle-related genes and two dormancy-related genes in M. canettii, M. tuberculosis H37Rv, and M. tuberculosis Beijing during the Wayne model of dormancy. The results showed that under hypoxic conditions the three tuberculosis genotypes were able to transcribe genes involved in DNA replication and cellular division. In addition, dosR was found to be up-regulated in M. tuberculosis Beijing during the exponential growth phase but down-regulated under hypoxic conditions. In this genotype, the replication-related gene dnaA was also strongly down-regulated. These latter two findings suggest that, compared to M. tuberculosis H37Rv and M. canettii, the Beijing genotype has a lower capacity to synthesize dosR, hspX, and dnaA mRNAs during in vitro dormancy.
authors.affiliation: Departament of Microbiology, National School of Biological Sciences, National Polytechnical Institute, Mexico DF, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Badillo-López
authors.forename: Arturo
authors.initials: A
authors.lastname: González-Mejía
authors.forename: A Cecilia
authors.initials: AC
authors.lastname: Helguera-Repetto
authors.forename: Laura P
authors.initials: LP
authors.lastname: Salas-Rangel
authors.forename: Sandra
authors.initials: S
authors.lastname: Rivera-Gutiérrez
authors.forename: Jorge F
authors.initials: JF
authors.lastname: Cerna-Cortés
authors.forename: José A
authors.initials: JA
authors.lastname: González-Y-Merchand
mesh_terms: D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D000860:Hypoxia; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D011494:Protein Kinases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; C542863:DosR protein, Mycobacterium tuberculosis; C118127:HspX protein, Mycobacterium tuberculosis; D012333:RNA, Messenger; D011494:Protein Kinases; D010100:Oxygen