Sammons C C, Sweet C
School of Biological Sciences, University of Birmingham, U.K.
J Gen Virol. 1989 Sep;70 ( Pt 9):2373-81. doi: 10.1099/0022-1317-70-9-2373.
To study the pathogenicity of murine cytomegalovirus (MCMV) and to identify virulence determinants, we have isolated and phenotypically characterized a set of temperature-sensitive mutants. One mutant, PP269/38, was avirulent for 1-week-old BALB/c mice and restricted in its plaque formation and replication at 39 degrees C. Mutants PP242/68 and PP268/38 were 100-fold less virulent than salivary gland-grown virus (SGV), even after two passages in the salivary glands of 1-week-old mice. The former mutant was unable to replicate or form plaques at 39 degrees C whereas the latter replicated poorly at 39 degrees C but not at all at 40 degrees C although it was able to form plaques at 40 degrees C with a reduced plaque size. PP31/15 exhibited a 40-fold reduction in virulence compared to SGV after two passages in vivo and was unable to form plaques or to replicate at 40 degrees C; at 39 degrees C it was able to, with reduced efficiency. The remaining two mutants, PP99/3 and PP392/31, were 10-fold less virulent than SGV and were restricted at 40 degrees C. The six mutants have been classified into at least four complementation groups. These mutants may be useful for studying various aspects of MCMV pathogenicity.
为研究鼠巨细胞病毒（MCMV）的致病性并鉴定毒力决定因素，我们分离并对一组温度敏感突变体进行了表型特征分析。一个突变体PP269/38对1周龄的BALB/c小鼠无毒力，在39℃时其蚀斑形成和复制受到限制。突变体PP242/68和PP268/38的毒力比唾液腺培养病毒（SGV）低100倍，即使在1周龄小鼠的唾液腺中传代两次后也是如此。前一个突变体在39℃时无法复制或形成蚀斑，而后一个突变体在39℃时复制不佳，但在40℃时完全不复制，尽管它在40℃时能够形成蚀斑，但其蚀斑尺寸减小。PP31/15在体内传代两次后，与SGV相比毒力降低了40倍，在40℃时无法形成蚀斑或复制；在39℃时它能够复制，但效率降低。其余两个突变体PP99/3和PP392/31的毒力比SGV低10倍，在40℃时受到限制。这六个突变体已被分为至少四个互补组。这些突变体可能有助于研究MCMV致病性的各个方面。
