title: Comparative Sigma Factor-mRNA Levels in Mycobacterium marinum under Stress Conditions and during Host Infection.
abstract: We have used RNASeq and qRT-PCR to study mRNA levels for all σ-factors in different Mycobacterium marinum strains under various growth and stress conditions. We also studied their levels in M. marinum from infected fish and mosquito larvae. The annotated σ-factors were expressed and transcripts varied in relation to growth and stress conditions. Some were highly abundant such as sigA, sigB, sigC, sigD, sigE and sigH while others were not. The σ-factor mRNA profiles were similar after heat stress, during infection of fish and mosquito larvae. The similarity also applies to some of the known heat shock genes such as the α-crystallin gene. Therefore, it seems probable that the physiological state of M. marinum is similar when exposed to these different conditions. Moreover, the mosquito larvae data suggest that this is the state that the fish encounter when infected, at least with respect to σ-factor mRNA levels. Comparative genomic analysis of σ-factor gene localizations in three M. marinum strains and Mycobacterium tuberculosis H37Rv revealed chromosomal rearrangements that changed the localization of especially sigA, sigB, sigD, sigE, sigF and sigJ after the divergence of these two species. This may explain the variation in species-specific expression upon exposure to different growth conditions.
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: B M Fredrik
authors.initials: BM
authors.lastname: Pettersson
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: Sarbashis
authors.initials: S
authors.lastname: Das
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: Phani Rama Krishna
authors.initials: PR
authors.lastname: Behra
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Heather R
authors.initials: HR
authors.lastname: Jordan
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: Malavika
authors.initials: M
authors.lastname: Ramesh
authors.affiliation: Department of Biology, University of Louisiana, Lafayette, Louisiana, United States of America.
authors.forename: Amrita
authors.initials: A
authors.lastname: Mallick
authors.affiliation: Department of Biology, University of Louisiana, Lafayette, Louisiana, United States of America.
authors.forename: Kate M
authors.initials: KM
authors.lastname: Root
authors.affiliation: Department of Biology, University of Louisiana, Lafayette, Louisiana, United States of America.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Cheramie
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: Irma
authors.initials: I
authors.lastname: de la Cruz Melara
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Pamela L C
authors.initials: PL
authors.lastname: Small
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: Santanu
authors.initials: S
authors.lastname: Dasgupta
authors.affiliation: Department of Biology, University of Louisiana, Lafayette, Louisiana, United States of America.
authors.forename: Don G
authors.initials: DG
authors.lastname: Ennis
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University Biomedical Centre, Uppsala, Sweden.
authors.forename: Leif A
authors.initials: LA
authors.lastname: Kirsebom
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D009033:Culicidae / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D018869:Heat-Shock Response / Q000235:genetics*; D007814:Larva / Q000382:microbiology; D019910:Mycobacterium marinum / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics*; D012808:Sigma Factor / Q000235:genetics*; D013045:Species Specificity; D013312:Stress, Physiological / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics; D038201:alpha-Crystallins / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D012808:Sigma Factor; D038201:alpha-Crystallins