Travis S L, Mendelson N H
Mol Gen Genet. 1977 Feb 15;150(3):309-16. doi: 10.1007/BF00268130.
The temperature-sensitive mutation in Bacillus subtilis 168-134ts, a conditional lethal DNA initiation mutant, was transferred to the minicell producing strain, CU 403 div IV-B1, to study he relationship of DNA synthesis to cell division. Markers in the combined mutant were verified by transduction. DNA replication kinetics, genome location by autoradiography, and clonal analysis of cell division patterns during spore outgrowths were investigated. Growth of the double mutant at the restrictive temperature results in an impressive reduction of the percentage cell length covered by DNA grain clusters (60.2% at 30 degrees C compared to 8.6% after 2 h at 45 degress C). The probability of a minicell producing division in double mutant clones is essentially the same at 30 degrees C and during the initial 2-3 h growth at 45 degrees C at which time lysis begins. Residual division at 45 degrees C is attributable to processes initiated at 30 degrees C. The CU 403 div IV-B1, 134ts, double mutant divides about 25% as frequently relative to growth as do wild type CU 403 clones when incubated at permissive temperature. This is approximately 15% greater division suppression than previously found in the CU 403 div IV-B1 mutant strain, and is presumably due to interactions of the mutant gene products both of which affect DNA.
枯草芽孢杆菌168 - 134ts中的温度敏感突变体是一种条件致死性DNA起始突变体，将其转移至产微小细胞的菌株CU 403 div IV - B1中，以研究DNA合成与细胞分裂的关系。通过转导验证了复合突变体中的标记。研究了DNA复制动力学、通过放射自显影确定的基因组定位以及芽孢萌发过程中细胞分裂模式的克隆分析。双突变体在限制温度下生长导致DNA颗粒簇覆盖的细胞长度百分比显著降低（30℃时为60.2%，而45℃处理2小时后为8.6%）。双突变体克隆中产生微小细胞分裂的概率在30℃时以及在45℃最初2 - 3小时的生长期间（此时开始裂解）基本相同。45℃时的残留分裂归因于在30℃时启动的过程。当在允许温度下培养时，CU 403 div IV - B1、134ts双突变体的分裂频率相对于生长而言约为野生型CU 403克隆的25%。这比之前在CU 403 div IV - B1突变体菌株中发现的分裂抑制大约高15%，推测这是由于两种都影响DNA的突变基因产物之间的相互作用所致。
