Ping Liyan, Weiner Beth, Kleckner Nancy
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Mol Microbiol. 2008 Sep;69(6):1427-38. doi: 10.1111/j.1365-2958.2008.06372.x. Epub 2008 Jul 18.
In Escherichia coli, the chemotaxis receptor protein Tsr localizes abundantly to cell poles. The current study, utilizing a Tsr-GFP fusion protein and time-lapse fluorescence microscopy of individual cell lineages, demonstrates that Tsr accumulates approximately linearly with time at the cell poles and that, in consequence, more Tsr is present at the old pole of each cell than at its newborn pole. The rate of pole-localized Tsr accumulation is large enough that old and new poles can always be reliably distinguished, even for cells whose old poles have had only one generation to accumulate signal. Correspondingly, Tsr-GFP can be reliably used to assign new and old poles to any cell without use of information regarding pole heritage, thus providing a useful tool to analyse cells whose prior history is not available. The absolute level of Tsr-GFP at the old pole of a cell also provides a rough estimate of pole (and thus cell) age.
在大肠杆菌中，趋化性受体蛋白Tsr大量定位于细胞两极。当前的研究利用Tsr-GFP融合蛋白以及对单个细胞谱系进行延时荧光显微镜观察，结果表明Tsr在细胞两极随时间大致呈线性积累，因此每个细胞的旧极比新极含有更多的Tsr。Tsr在两极积累的速率足够大，以至于即使对于那些旧极仅有一代时间来积累信号的细胞，旧极和新极也总能被可靠地区分。相应地，即使不使用有关极的遗传信息，Tsr-GFP也能可靠地用于区分任何细胞的新旧两极，从而为分析那些没有先前历史信息的细胞提供了一个有用的工具。细胞旧极处Tsr-GFP的绝对水平也能大致估算极（进而细胞）的年龄。
