Single-molecule imaging correlates decreasing nuclear volume with increasing TF-chromatin associations during zebrafish development
Single-molecule imaging correlates decreasing nuclear volume with increasing TF-chromatin associations during zebrafish development
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DOI：
10.1038/s41467-018-07731-8
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发表时间：
2017-10
影响因子：
16.6
通讯作者：
M. Reisser;A. Palmer;Achim P. Popp;C. Jahn;G. Weidinger;J. Gebhardt
中科院分区：
文献类型：
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作者：
M. Reisser;A. Palmer;Achim P. Popp;C. Jahn;G. Weidinger;J. Gebhardt
合子基因组激活(ZGA)是许多物种在最初静止后开始转录的一个主要发育阶段，发生在斑马鱼胚胎的10个细胞分裂之后。转录因子(TF)-染色质相互作用在早期发育过程中如何进化以支持ZGA在很大程度上尚不清楚。我们利用反射光片显微镜在斑马鱼活胚胎发育过程中建立了单分子示踪，以显示两个荧光标记的转铁蛋白物种，mEos2-TBP和mEos2-Sox19b。我们进一步开发了一个数据采集和分析方案，以提取快速细胞周期中结合动力学和结合组分的定量信息。这两种转录因子的染色质结合比例在早期发育期间增加，正如从转录因子-染色质相互作用的物理模型中预期的那样，包括核体积减少和DNA可及性增加。对于Sox19b，数据表明增加的主要原因是原子核的缩小。我们的单分子方法提供了包含ZGA的发育期间TF-染色质关联的变化的定量洞察力。
Zygotic genome activation (ZGA), the onset of transcription after initial quiescence, is a major developmental step in many species, which occurs after ten cell divisions in zebrafish embryos. How transcription factor (TF)-chromatin interactions evolve during early development to support ZGA is largely unknown. We establish single molecule tracking in live developing zebrafish embryos using reflected light-sheet microscopy to visualize two fluorescently labeled TF species, mEos2-TBP and mEos2-Sox19b. We further develop a data acquisition and analysis scheme to extract quantitative information on binding kinetics and bound fractions during fast cell cycles. The chromatin-bound fraction of both TFs increases during early development, as expected from a physical model of TF-chromatin interactions including a decreasing nuclear volume and increasing DNA accessibility. For Sox19b, data suggests the increase is mainly due to the shrinking nucleus. Our single molecule approach provides quantitative insight into changes of TF-chromatin associations during the developmental period embracing ZGA.