细菌mRNA转录后的扩散

由于在细菌被膜封闭的腔室中没有进行区隔，因此难以确定成熟信使RNA（mRNA）是怎样在细胞内分布的。Llopis等人利用荧光实验（这种实验很难做，因为细菌太小）来跟踪转录后mRNA的扩散。他们发现，出人意料的是，新转录的mRNA所表现出的扩散很有限。

Eukaryotic cells spatially organize mRNA processes such as translation and mRNA decay. Much less is clear in bacterial cells where the spatial distribution of mature mRNA remains ambiguous. Using a sensitive method based on quantitative fluorescence in situ hybridization, we show here that in Caulobacter crescentus and Escherichia coli, chromosomally expressed mRNAs largely display limited dispersion from their site of transcription during their lifetime. We estimate apparent diffusion coefficients at least two orders of magnitude lower than expected for freely diffusing mRNA, and provide evidence in C. crescentus that this mRNA localization restricts ribosomal mobility. Furthermore, C. crescentus RNase E appears associated with the DNA independently of its mRNA substrates. Collectively, our findings show that bacteria can spatially organize translation and, potentially, mRNA decay by using the chromosome layout as a template.

他们猜测，堆积的染色体材料可能自己充当了一个区隔，来将转录与 mRNA降解分开。