Ollington J F, Losick R
J Bacteriol. 1981 Aug;147(2):443-51. doi: 10.1128/jb.147.2.443-451.1981.
Cells of Bacillus subtilis synthesize a relatively long-lived ribonucleic acid (RNA) of about 300 bases during the course of spore formation. This transcript does not appear until an intermediate stage (III or IV) of development but is the predominant sporulation-specific transcript among RNAs of discrete size in late (stages IV to VI) developing cells. Appearance of the 300-base RNA is under sporulation control as this transcript could not be detected in cells of an early-blocked sporulation mutant (Spo0A). We have located the coding sequence for the 300-base RNA within a cloned chromosomal segment from the purA-cysA region that was previously shown to contain a cluster of genes that are actively transcribed during sporulation. The coding sequence for the 300-base RNA (designated as the 0.3 kb gene) mapped between a gene (veg) that was actively transcribed during growth and development and a gene (0.4 kb) that was turned on at the onset of sporulation. Although clustered within a small segment of the chromosome, the veg, 0.3 kb, and 0.4 kb transcription units exhibited, therefore, distinct patterns of temporally programmed gene expression. Models for the activation of the 0.3 kb gene at an intermediate stage of development are discussed.
枯草芽孢杆菌的细胞在芽孢形成过程中会合成一种相对寿命较长、约300个碱基的核糖核酸（RNA）。这种转录本直到发育的中间阶段（III期或IV期）才出现，但在后期（IV期至VI期）发育细胞中离散大小的RNA中，它是主要的芽孢形成特异性转录本。300碱基RNA的出现受芽孢形成控制，因为在早期阻断芽孢形成的突变体（Spo0A）细胞中检测不到这种转录本。我们已将300碱基RNA的编码序列定位在来自purA-cysA区域的一个克隆染色体片段内，该区域先前已显示含有一组在芽孢形成过程中被积极转录的基因。300碱基RNA的编码序列（命名为0.3 kb基因）定位于一个在生长和发育过程中被积极转录的基因（veg）与一个在芽孢形成开始时开启的基因（0.4 kb）之间。因此，尽管veg、0.3 kb和0.4 kb转录单元聚集在染色体的一小段区域内，但它们表现出不同的时间程序性基因表达模式。文中讨论了在发育中间阶段激活0.3 kb基因的模型。
