BACTERIOPHAGE T4 RI MUTATIONS

突变导致人类遗传性出生缺陷的负担 癌症和心脏病也有可能。 噬菌体 T4已被广泛用作分析机制的模型系统 诱变的结果。 最常见的T4突变检测之一 通过其大的、尖锐的边缘识别r（快速裂解）突变体 斑块 尽管rII突变体是最常被 为了进一步分析，大多数诱变剂产生的rI多于rII 变种人 由于对rI突变体知之甚少， 研究了它们的遗传特性 突变产生了 特征性rI表型出现在两个位点，一个是经典的 在标准地图上描述了大约1：30的焦点，另一个a 地点在八点半左右 1：30位点的点突变重组 在低频率下感兴趣，这表明一个小基因;有几个是 被未连锁但尚未定位的抑制基因突变所抑制。 “8：30”的位置正在被更紧密地绘制。

Mutagens contribute to the human burden of heritable birth defects and cancer and probably to heart disease as well. Bacteriophage T4 has been widely employed as a model system to analyze mechanisms of mutagenesis. One of the most common T4 mutation assays recognizes r (rapid lysis) mutants by their large, sharply edged plaques. Although the rII mutants are those most often subjected to further analysis, most mutagens produce more rI than rII mutants. Since little is known about the rI mutants, we have investigated their genetic properties. Mutations that produce the characteristic rI phenotype arise at two loci, one the classically described focus at about 1:30 on the standard map and another a locus at about 8:30. Point mutations at the 1:30 locus recombine inter se at low frequencies, suggesting a small gene; several are suppressed by unlinked but as yet unmapped suppressor mutations. The "8:30" locus is being more closely mapped.