Tiraby G, Fox M S, Bernheimer H
J Bacteriol. 1975 Feb;121(2):608-18. doi: 10.1128/jb.121.2.608-618.1975.
The function responsible for discrimination among markers (point mutations) in Pneumococcus (hex) was traced back to the early strains used to demonstrate the chemical basis of transformation in the early 1940s. Those currently used laboratory strains failing to manifest this function arose from a single subline of the original strain. The function was also evident in other independently isolated strains including a number of different serological types. The hex function was not evident in transformation between heterologous pneumococcal strains probably as a result of the sensitivity of the function to saturation in the presence of deoxyribonucleic acid from closely related but nonisogenic strains.
负责鉴别肺炎链球菌（hex）中标记物（点突变）的功能可追溯到20世纪40年代初用于证明转化化学基础的早期菌株。目前使用的无法表现出该功能的实验室菌株源自原始菌株的一个单一亚系。该功能在其他独立分离的菌株中也很明显，包括许多不同的血清型。hex功能在异源肺炎链球菌菌株之间的转化中不明显，这可能是由于该功能在存在来自密切相关但非同源菌株的脱氧核糖核酸时对饱和敏感。
