饥饿时，枯草芽胞杆菌(Bacillus subtilis)进入芽孢形成(sporulation)过程，该过程持续几个小时，最终形成已知的适应性最强的细胞类型，即芽孢。研究人员证实在芽孢形成几天之后，芽孢的RNA谱(RNA profile)是高度动态变化的。2011年12月29日，该研究结果发表在《细胞》期刊上。
在高温培育的老化芽孢中，RNA含量在几天之内发生降解而全局性地下降。这种降解可能是芽孢利用的一种策略以便促进它进入休眠。然而在低温中保存的芽孢表现出不同的促进转录的RNA谱。
再者，研究人员证实芽孢萌发(germination)受芽孢年龄、培育温度和RNA状态的影响，这就意味着芽孢在被认为是休眠状态的时间里能够获得不同的特点。研究人员认为，不同于当前的想法，进入休眠需持续几天，在这当中芽孢受环境的影响，并经历着影响它们萌发的相应分子变化。
综上所述，细菌芽孢在被认为是休眠状态的时间里，它的RNA谱是动态变化的；在高温培育的老化芽孢的RNA含量因受到降解而下降；低温保存的芽孢在芽孢形成后几天，发生显著的RNA转录；芽孢萌发受芽孢年龄、培育时间和RNA状态的影响。(生物谷：towersimper编译)
doi:10.1016/j.cell.2011.11.059
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RNA Dynamics in Aging Bacterial Spores
Einat Segev, Yoav Smith, Sigal Ben-Yehuda
Upon starvation, the bacterium Bacillus subtilis enters the process of sporulation, lasting several hours and culminating in formation of a spore, the most resilient cell type known. We show that a few days following sporulation, the RNA profile of spores is highly dynamic. In aging spores incubated at high temperatures, RNA content is globally decreased by degradation over several days. This degradation might be a strategy utilized by the spore to facilitate its dormancy. However, spores kept at low temperature exhibit a different RNA profile with evidence supporting transcription. Further, we demonstrate that germination is affected by spore age, incubation temperature, and RNA state, implying that spores can acquire dissimilar characteristics at a time they are considered dormant. We propose that, in contrast to current thinking, entering dormancy lasts a few days, during which spores are affected by the environment and undergo corresponding molecular changes influencing their emergence from quiescence.
