Hamilton D L, Luftig R B
J Virol. 1972 Jun;9(6):1047-56. doi: 10.1128/JVI.9.6.1047-1056.1972.
The nature of phage precursors in gene 13-defective infected cells was studied by electron microscopy and pulse-chase isotopic labeling experiments. Our results suggest that both stable (20%) and fragile (70%) filled-head precursors accumulated in the absence of gene 13 product. Upon extraction, the fragile heads were found to lose most of their deoxyribonucleic acid and appeared unfilled with an average density of 1.34 g/cm(3) and a sedimentation coefficient of 300S. These unfilled heads differed from empty gene 13-defective heads which did not have any associated deoxyribonucleic acid and banded at an average density of 1.31 g/cm(3). Furthermore, it was found that a tsN38 (temperature-sensitive mutant in gene 13)- infected culture maintained at 41.5 C for increasing times led to a decrease in specific infectivity of 1,000S phagelike particles. Electron microscopy of these particles revealed that the decreased infectivity was due to an improper union of head and tails.
通过电子显微镜和脉冲追踪同位素标记实验研究了基因13缺陷感染细胞中噬菌体前体的性质。我们的结果表明，在没有基因13产物的情况下，稳定的（20%）和易碎的（70%）满头部前体都会积累。提取后发现，易碎头部失去了大部分脱氧核糖核酸，看起来未被填满，平均密度为1.34 g/cm³，沉降系数为300S。这些未填满的头部与空的基因13缺陷头部不同，后者没有任何相关的脱氧核糖核酸，平均密度为1.31 g/cm³。此外，还发现将tsN38（基因13中的温度敏感突变体）感染的培养物在41.5℃下维持较长时间会导致1000S噬菌样颗粒的比感染性降低。对这些颗粒的电子显微镜观察表明，感染性降低是由于头部和尾部结合不当所致。
