Genome-wide transcriptional analysis of temperature shift in L. interrogans serovar lai strain 56601.
BACKGROUND
Leptospira interrogans is an important mammalian pathogen. Transmission from an environmental source requires adaptation to a range of new environmental conditions in the organs and tissues of the infected host. Several studies have shown that a shift in culture temperature from 28 degrees C to 37 degrees C, similar to that encountered during infection of a host from an environmental source, is associated with differential synthesis of several proteins of the outer membrane, periplasm and cytoplasm. The whole genome of the Leptospira interrogans serogroup Icterohaemorrhagiae serovar lai type strain #56601 was sequenced in 2003 and microarrays were constructed to compare differential transcription of the whole genome at 37 degrees C and 28 degrees C.


RESULTS
DNA microarray analyses were used to investigate the influence of temperature on global gene expression in L. interrogans grown to mid-exponential phase at 28 degrees C and 37 degrees C. Expression of 106 genes differed significantly at the two temperatures. The differentially expressed genes belonged to nine functional categories: Cell wall/membrane biogenesis genes, hemolysin genes, heat shock proteins genes, intracellular trafficking and secretion genes, two-component system and transcriptional regulator genes, information storage and processing genes, chemotaxis and flagellar genes, metabolism genes and genes with no known homologue. Real-time reverse transcription-PCR assays confirmed the microarray data.


CONCLUSIONS
Microarray analyses demonstrated that L. interrogans responds globally to temperature alteration. The data delineate the spectrum of temperature-regulated gene expression in an important human pathogen and provide many new insights into its pathogenesis.
Qin
Jin-Hong
JH
School of Life Science/Chemical Engineering, Sichuan University, Chengdu 610041, PR China. Jinhongq@hotmail.com
Sheng
Yue-Ying
YY
Zhang
Zhi-Ming
ZM
Shi
Yao-Zhou
YZ
He
Ping
P
Hu
Bao-Yu
BY
Yang
Yang
Y
Liu
Shi-Gui
SG
Zhao
Guo-Ping
GP
Guo
Xiao-Kui
XK
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial / Q000235:genetics*; D006801:Humans; D007921:Leptospira interrogans / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D013696:Temperature; D014158:Transcription, Genetic
D001426:Bacterial Proteins