Use of temperature-sensitive mutants to study gene expression during sporulation in Bacillus subtilis
Use of temperature-sensitive mutants to study gene expression during sporulation in Bacillus subtilis
复制标题
使用温度敏感突变体研究枯草芽孢杆菌孢子形成过程中的基因表达
作者：
M. Young
两个温度敏感的孢子突变体已经被表征。一个突变体，在II期被阻断，有一个短暂的温度敏感期，大约发生在孢子间隔形成的时候。如果在允许的温度下孵育一段时间，细胞可以摆脱产孢阻滞，但转录和翻译抑制剂阻止了这一点；这表明，缺陷基因的产物是一种蛋白质，而编码这种蛋白质的信使核糖核酸是短命的。另一个突变体在IV期到V期被阻断，并且在III期开始有一个很长的温度敏感期，在突变缺陷表型表达的阶段之前。这个突变体在温度变化实验中的表现表明，缺陷基因产物的合成早在它承担其生理功能之前就开始了。
Two temperature-sensitive sporulation mutants have been characterized. One mutant, which is blocked at stage II, has a short temperature-sensitive period that occurs at about the time when the spore septum is formed. Cells can escape the sporulation block, if incubated for a short period at the permissive temperature, but are prevented from doing so by inhibitors of transcription and translation; this suggests that the product of the defective gene is a protein and that the messenger ribonucleic acid which codes for this protein is short-lived. The other mutant is blocked at stage IV to V and has a long temperature-sensitive period that starts during stage III and precedes the stage at which the mutational defect is phenotypically expressed. The behavior of this mutant in temperature-shift experiments suggests that synthesis of the product of the defective gene commences long before it assumes its physiological function.