Developmental Biomedicine Research Group, Faculty of Medical and Human Sciences, AV Hill Building, University of Manchester, Manchester M13 9PT, UK.
J Cell Sci. 2011 Oct 15;124(Pt 20):3484-91. doi: 10.1242/jcs.088500. Epub 2011 Oct 7.
Important questions in biology have emerged recently concerning the timing of transcription in living cells. Studies on clonal cell lines have shown that transcription is often pulsatile and stochastic, with implications for cellular differentiation. Currently, information regarding transcriptional activity at cellular resolution within a physiological context remains limited. To investigate single-cell transcriptional activity in real-time in living tissue we used bioluminescence imaging of pituitary tissue from transgenic rats in which luciferase gene expression is driven by a pituitary hormone gene promoter. We studied fetal and neonatal pituitary tissue to assess whether dynamic patterns of transcription change during tissue development. We show that gene expression in single cells is highly pulsatile at the time endocrine cells first appear but becomes stabilised as the tissue develops in early neonatal life. This stabilised transcription pattern might depend upon tissue architecture or paracrine signalling, as isolated cells, generated from enzymatic dispersion of the tissue, display pulsatile luminescence. Nascent cells in embryonic tissue also showed coordinated transcription activity over short distances further indicating that cellular context is important for transcription activity. Overall, our data show that cells alter their patterns of gene expression according to their context and developmental stage, with important implications for cellular differentiation.
最近，生物学领域出现了一些重要问题，涉及活细胞中转录的时间。对克隆细胞系的研究表明，转录通常是脉冲式和随机的，这对细胞分化有影响。目前，关于生理环境下细胞分辨率内转录活性的信息仍然有限。为了在活体组织中实时研究单细胞转录活性，我们使用荧光素酶基因表达受垂体激素基因启动子驱动的转基因大鼠的垂体组织进行生物发光成像。我们研究了胎儿和新生儿的垂体组织，以评估转录的动态模式是否在组织发育过程中发生变化。我们表明，内分泌细胞首次出现时，单个细胞中的基因表达高度脉冲式，但随着组织在新生儿早期的发育，它变得稳定。这种稳定的转录模式可能依赖于组织架构或旁分泌信号，因为从组织的酶解分散中产生的分离细胞显示出脉冲式的发光。胚胎组织中的新生细胞也显示出短距离的协调转录活性，这进一步表明细胞环境对转录活性很重要。总的来说，我们的数据表明，细胞根据其环境和发育阶段改变其基因表达模式，这对细胞分化有重要影响。
