【摘要】：目的研究溫度和酸度對田鼠型鼠疫耶爾森菌psa位點的轉(zhuǎn)錄調(diào)控作用。方法首先設(shè)計相關(guān)跨基因引物,用RT-PCR方法驗證psa位點的相關(guān)操縱子結(jié)構(gòu)。擴增操縱子首基因上游啟動子區(qū)500 nt序列,并克隆入pRW50質(zhì)粒β-半乳糖苷酶基因的上游,將重組質(zhì)粒轉(zhuǎn)入鼠疫菌中,通過測定β-半乳糖苷酶活性差異來判斷不同溫度(26和37℃)和酸度(pH 6.0和pH 8.0)對psaE和psaA的調(diào)控關(guān)系。最后提取鼠疫菌在上述不同溫度和酸度條件下的總RNA,采用引物延伸實驗進一步明確溫度和酸度對psaA的調(diào)控關(guān)系。結(jié)果與結(jié)論 RT-PCR結(jié)果證實了田鼠型鼠疫菌的psa位點由操縱子psaEF和psaABC構(gòu)成;半乳糖苷酶和引物延伸實驗結(jié)果顯示在37℃、pH 6.0培養(yǎng)條件下psaABC的轉(zhuǎn)錄水平最高,而psaEF的轉(zhuǎn)錄水平無明顯變化,提示psaA的表達水平在37℃酸性條件下表達量最高,psaE則不受溫度和酸度的調(diào)控。
[Abstract]:Objective To study the effect of temperature and acidity on the transcription and control of the psa site in the microvole-type Yersinia pestis. Methods The relative operon structure of the psa site was verified by RT-PCR. the sequence of the promoter region of the upstream promoter region of the first gene of the operon is amplified and cloned into the upstream of the pRW50 plasmid pRW50 plasmid, The regulation and control of psaE and psaA were determined by the determination of the difference of the activity of the yeast-galactooligosaccharides (pH 6.0 and pH 8.0) at different temperatures (26 and 37.degree. C.) and the acidity (pH 6.0 and pH 8.0). Finally, the total RNA of Yersinia pestis under different temperature and acidity conditions was extracted, and the control relationship of temperature and acidity to psa A was further determined by the primer extension experiment. The results and conclusions RT-PCR confirmed that the psa site of the microvole-type Yersinia pestis was composed of the operon psaEF and psaABC. The results showed that the transcription level of psaABC was the highest at 37 鈩，

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