Robin H, Parsons J A, Addison J, York C J
Can J Comp Med. 1972 Jul;36(3):294-302.
Large plaque (4LP) and small plaque (4SP) variants were derived from a parent bovine virus strain by serial plaque passage. Both 4LP and 4SP were resistant to chloroform and stabilized at 50 degrees C for one hour by 1.0 M magnesium chloride. Both 4LP and 4SP had buoyant densities in cesium chloride of 1.36 gm/ml. Antigenically, 4LP and 4SP were reciprocally cross neutralizable. The nucleic acid of 4LP was shown to be ribonucleic acid (RNA) by resistance of its infectivity to deoxynuclease (DNase) but not ribonuclease (RNase) and by increased incorporation of [(3)H]-uridine into cytoplasmic RNA in cells of virus infected cultures. In growth characteristics, both 4LP and 4SP had maximum adsorption times of 75 to 90 minutes but 4LP had more rapid replication and release rates and yielded nearly twice as many infectious units per cell as 4SP. The differences in growth properties correlated directly with the differential in plaque diameter which was 40-50%.
大噬斑（4LP）和小噬斑（4SP）变体是通过连续噬斑传代从一株牛病毒亲本毒株衍生而来的。4LP和4SP均对氯仿有抗性，并且在50摄氏度下用1.0 M氯化镁稳定一小时。4LP和4SP在氯化铯中的浮力密度均为1.36克/毫升。在抗原性方面，4LP和4SP可相互交叉中和。4LP的核酸经证明是核糖核酸（RNA），这是因为其感染性对脱氧核糖核酸酶（DNase）有抗性而对核糖核酸酶（RNase）没有抗性，并且在病毒感染培养物的细胞中，[（3）H] - 尿苷掺入细胞质RNA的量增加。在生长特性方面，4LP和4SP的最大吸附时间均为75至90分钟，但4LP具有更快的复制和释放速率，并且每个细胞产生的感染单位数量几乎是4SP的两倍。生长特性的差异与噬斑直径40 - 50%的差异直接相关。
