SARS冠状病毒的多组织嗜性及其全基因序列的测定

目的研究SARS冠状病毒对不同组织的感染情况，了解SARS流行初期病毒的基因组序列。方法用Trizol RNA抽提试剂提取因SARS病毒感染而死亡的3例死者不同组织中的总RNA，并逆转录为cDNA，然后用针对SARS病毒不同基因区间的引物进行PCR扩增，并对其中1例肺组织中病毒全序列进行了测定。结果3例病例中有2例仅在肺组织中扩增到病毒序列，另1例除在肺组织中检测到病毒外，还在气管、肾、淋巴结及肝组织中检测到病毒的存在。病毒全序列分析结果显示，该序列全长为29760个碱基，具有典型的冠状病毒序列特征，除具有RNA聚合酶基因和s、E、M和N4种结构蛋白基因外，还有另外8个蛋白编码框。经与GenBank上登录的部分其他SARS冠状病毒全序列进行比对，发现该序列除存在少量的SNP外，还多出一段29个核苷酸的序列，这段序列的存在完全改变了ORF10和ORF11两个蛋白编码框，使得在此终止的蛋白翻译能够继续进行下去，从而使ORF10和ORF11两个读框成为一个读框。结论SARS病毒具有多组织嗜性；该序列有可能是病毒从动物传到人的原始序列。

Analysis of multiple-tissue tropism and gene sequence of SARS-associated coronavirus

Objective To evaluate the infectivity of various human tissues to SARS associated coronavirus(SARS Cov), and to study the genome sequence of the virus at the initial stage of SARS epidemic. Methods The total genome RNA was extracted with TRIZOL reagent from various tissue specimens of three patients who died of SARS, and cDNA was obtained.PCR was performed using SARS Cov specific primers to amplify the various gene fragments of SARS Cov. A whole virus genome sequence was analyzed in a lung tissue specimen from one deed patient. Results The virus gene fragments was amplified from various tissue specimens of one dead patient, including the trachea, lung, kidney, liver and lymph nodes, but they were obtained only from the lung tissue specimens of two others. The results provided the whole sequence of 29745bp with typical coronavirus sequence characteristics, which not only contained the gene fragments of polymerase, spike protein, membrane protein, nucleocapsid protein, but also other 8 open reading fragments(ORFs). Compared with other whole coronavirus genome sequences in GenBank, it was shown that the sequence had a more gene fragment including 29 nucleotides besides a small quantity of SNP. The fragment was inserted between ORF10 and ORF11, which completely transformed two ORFs to one ORF, and made the ended protein translation to extend continuously. Conclusion The results demonstrate that SARS Cov is a multiple tissue tropism virus; on the other hand, this whole genome sequence could be the original sequence transmitted from animal to human.