Journal of Microbiology

Research Support, Non-U.S. Gov'ts

Parallel Gene Loss and Acquisition Among Strains of Different Brucella Species and Biovars: Zhijun Zhong , Yufei Wang , Jie Xu , Yanfen Chen , Yuehua Ke , Xiaoyan Zhou , Xitong Yuan , Dongsheng Zhou , Yi Yang , Ruifu Yang , Guangneng Peng , Hai Jiang , Jing Yuan , Hongbin Song , Buyun Cui , Liuyu Huang , Zeliang Chen; J. Microbiol. 2012;50(4):567-574. Published online August 25, 2012; DOI: https://doi.org/10.1007/s12275-012-2022-8

Abstract: The genus Brucella is divided into six species; of these, B. melitensis and B. abortus are pathogenic to humans, and B. ovis and B. neotomae are nonpathogenic to humans. The definition of gene loss and acquisition is essential for understanding Brucella’s ecology, evolutionary history, and host relationships. A DNA microarray containing unique genes of B. melitensis Type strain 16MT and B. abortus 9-941 was constructed and used to determine the gene contents of the representative strains of Brucella. Phylogenetic relationships were inferred from sequences of housekeeping genes. Gene loss and acquisition of different Brucella species were inferred. A total of 214 genes were found to be differentially distributed, and 173 of them were clustered into 15 genomic islands (GIs). Evidence of horizontal gene transfer was observed for 10 GIs. Phylogenetic analysis indicated that the 19 strains formed five clades, and some of the GIs had been lost or acquired independently among the different lineages. The derivation of Brucella lineages is concomitant with the parallel loss or acquisition of GIs, indicating a complex interaction between various Brucella species and hosts.

DNA Microarray-Based Global Transcriptional Profiling of Yersinia pestis in Multicellularity: Jingfu Qiu , Zhaobiao Guo , Haihong Liu , Dongsheng Zhou , Yanping Han , Ruifu Yang; J. Microbiol. 2008;46(5):557-563. Published online October 31, 2008; DOI: https://doi.org/10.1007/s12275-008-0140-0

Abstract: Yersinia pestis, the causative agent of plague, has a feature of forming multicellular aggregates at liquid-air interface around the wall of glass tube. In this study, we employed the whole-genome DNA microarray of Y. pestis to investigate the global transcriptional profile in multicellularity compared with that in its planktonic growth. A total of 177 genes were differentially expressed in Y. pestis during early stage of multicellular formation; Seventy genes of them were up-regulated while 107 down-regulated. In addition to a large number of genes encoding unknown functions, most of the induced genes encode cell envelope and transport/binding proteins. The up-regulation of amino acid biosynthesis, the differentially altered genes that are involved in virulence, and the cold shock protein genes were for the first time reported to be associated with the multicellular formation. Our results revealed the global gene expression of Y. pestis were changed in the formation of multicellularity, providing insights into the molecular mechanism of multicellular behaviour, which need investigating further.

Genome-Wide Transcriptional Responses to Sulfite in Saccharomyces cerevisiae: Hoon Park , Yoon-Sun Hwan; J. Microbiol. 2008;46(5):542-548. Published online October 31, 2008; DOI: https://doi.org/10.1007/s12275-008-0053-y

Abstract: Sulfite is a commonly used preservative in foods, beverages, and pharmaceuticals because it is toxic to many microorganisms. In order to understand the global response of Saccharomyces cerevisiae to sulfite, genome-wide transcript profiling following sulfite exposure was obtained. The transcription levels of 21 genes were increased more than 2-fold, while those of 37 genes decreased to a similar extent. Genes involved in carbohydrate metabolism represented the highest proportion of induced genes, which may account for the easily acquired resistance to sulfite. Most of down-regulated genes are involved in transcription, protein biosynthesis, and cell growth. The down-regulation of these genes is thought to reflect growth arrest which occurs during sulfite treatment, allowing cells to save energy. Cells treated with sulfite generated more than 70% of acetaldehyde than untreated cells, suggesting that the increased acetaldehyde production is correlated with the induction of PDC1 gene encoding pyruvate decarboxylase.

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