Project description:Purpose: In previous studies, we found that the fyuA gene plays an important role in the virulence and pathogenicity of Yersinia pestis strain 201. In order to globally observe which functions of the fyuA gene also affect Y. pestis, we performed RNA-seq on the Y. pestis wild strain 201-WT and mutant strains △fyuA and △fyuAGCAdel, hoping to find their differences at the transcription level, so that better elucidate the effect of fyuA gene on Y. pestis gene transcription. Methods: Total RNA was extracted using the PureLink™ RNA Mini Kit, and then used for creating a cDNA library and deep sequencing. According to the values of Fragments Per Kilobase of Transcript per Million Mapped Reads (FPKM), the ratio of transcript levels between WT and ΔfyuAGCAdel groups was used as the logarithm to the base 2 (twofold change). The differential values of at least a 2-fold were applied to analyze the differential expression of genes according to the Y. pestis 91001 genome annotation. The transcriptome data were verified by qPCR. Results: We found that compared with 201-WT, genes related to siderophore synthesis such as ybtS, ybtX, ybtQ, irp2, irp1, ybtU, ybtT and ybtE were significantly down-regulated at either 26 ℃ or 37 ℃. At 37 ℃, the genes related to type Ⅲ secretion system were significantly up-regulated.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of autoinducer 2 (AI-2) quorum sensing was investigated by comparing transcript profiles when luxS gene was knocked out. The luxS gene encodes S-ribosylhomocysteinase which can produce DPD, a precursor of AI-2. The strain ∆pgm (pigmentation-negative) mutant R88 was called wild type. The ∆pgm ∆luxS mutant was called control.
