Episodic evolution mediates interspecies transfer of a murine coronavirus
Episodic evolution mediates interspecies transfer of a murine coronavirus
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DOI：
10.1128/jvi.71.3.1946-1955.1997
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发表时间：
1997-03-01
影响因子：
5.4
通讯作者：
Chen, W
中科院分区：
文献类型：
--
作者：
Baric, RS;Yount, B;Chen, W
允许在新近采用的宿主物种中建立和传播病毒的分子机制，对小鼠肝炎病毒（MHV）菌株（MHV-A59，MHV-JHM，MHV-JHM和MHV-A59/MHV-JHM）均被循环中的混合培养物中传递包含逐渐增加的非疗程叙利亚仓鼠肾（BHK）细胞和允许鼠DBT细胞的浓度降低。从MHV-A59/MHW-JHM混合感染中，在相同的治疗条件下，在BHK细胞中有效复制的变体病毒（MHV-H1和MHV-H2）有效地复制病毒或转录病毒RNA或蛋白质的可检测水平，MHV-H分离株是多营养的，在正常非疗程的叙利亚仓鼠平滑肌（DDTT-1）中有效复制vero）和鼠17cl-1细胞系。几乎没有在猫肾（CRFK）和猪睾丸（ST）细胞系中检测到任何病毒复制。变体病毒MHV-H2在相对丰度和大小上转录了七个mRNA，其大小与父母病毒菌株合成的mRNA。 MHV-H2是一种RNA重组病毒，该病毒含有S糖蛋白基因中的跨界部位。在分子水平上，情节进化和达尔文阳性自然选择在MHV-H2 s中显而易见，他是糖蛋白基因，这些发现与中性变化是分子进化的主要特征，并认为改变生态的生态进化的假说是不同的。支配种间转移并扩散到替代宿主的种间传递的MHV尖峰糖蛋白基因。
Molecular mechanisms permitting the establishment and dissemination of a virus within a newly adopted host species are poorly understood, Mouse hepatitis virus (MHV) strains (MHV-A59, MHV-JHM, and MHV-A59/MHV-JHM) were passaged in mixed cultures containing progressively increasing concentrations of nonpermissive Syrian baby hamster kidney (BHK) cells and decreasing concentrations of permissive murine DBT cells. From MHV-A59/MHW-JHM mixed infection, variant viruses (MHV-H1 and MHV-H2) which replicated efficiently in BHK cells were isolated, Under identical treatment conditions, the parental MHV-A59 or MHV-JHM strains failed to produce infectious virus or transcribe detectable levels of viral RNA or protein, The MHV-H isolates were polytrophic, replicating efficiently in normally nonpermissive Syrian hamster smooth muscle (DDT-1), Chinese hamster ovary (CHO), human adenocarcinoma (HRT), primate kidney (Vero), and murine 17Cl-1 cell lines. Little if any virus replication was detected in feline kidney (CRFK) and porcine testicular (ST) cell lines. The variant virus, MHV-H2, transcribed seven mRNAs equivalent in relative abundance and size to those synthesized by the parental virus strains. MHV-H2 was an RNA recombinant virus containing a crossover site in the S glycoprotein gene. At the molecular level, episodic evolution and positive Darwinian natural selection were apparent within the MHV-H2 S and HE glycoprotein genes, These findings differ from the hypothesis that neutral changes are the predominant feature of molecular evolution and argue that changing ecologies actuate episodic evolution in the MHV spike glycoprotein genes that govern interspecies transfer and spread into alternative hosts.