Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
Cell Rep. 2013 Jan 31;3(1):8-15. doi: 10.1016/j.celrep.2012.12.015. Epub 2013 Jan 24.
Transcription is commonly held to be a highly stochastic process, resulting in considerable heterogeneity of gene expression among the different cells in a population. Here, we employ quantitative in situ hybridization methods coupled with high-resolution imaging assays to measure the expression of snail, a developmental patterning gene necessary for coordinating the invagination of the mesoderm during gastrulation of the Drosophila embryo. Our measurements of steady-state mRNAs suggest that there is very little variation in snail expression across the different cells that make up the mesoderm and that synthesis approaches the kinetic limits of Pol II processivity. We propose that rapid transcription kinetics and negative autoregulation are responsible for the remarkable homogeneity of snail expression and the coordination of mesoderm invagination.
转录通常被认为是一个高度随机的过程，导致群体中不同细胞的基因表达存在很大的异质性。在这里，我们采用定量原位杂交方法结合高分辨率成像分析来测量 snail 的表达，snail 是一种发育模式基因，对于协调果蝇胚胎原肠胚形成过程中的中胚层内陷是必需的。我们对稳定态 mRNA 的测量表明，组成中胚层的不同细胞中 snail 的表达变化很小，并且合成接近 Pol II 延伸性的动力学极限。我们提出，快速的转录动力学和负反馈调节是 snail 表达的显著均匀性和中胚层内陷协调的原因。
