Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, United States.
Elife. 2021 Mar 15;10:e66668. doi: 10.7554/eLife.66668.
Following fertilization, the genomes of the germ cells are reprogrammed to form the totipotent embryo. Pioneer transcription factors are essential for remodeling the chromatin and driving the initial wave of zygotic gene expression. In , the pioneer factor Zelda is essential for development through this dramatic period of reprogramming, known as the maternal-to-zygotic transition (MZT). However, it was unknown whether additional pioneer factors were required for this transition. We identified an additional maternally encoded factor required for development through the MZT, GAGA Factor (GAF). GAF is necessary to activate widespread zygotic transcription and to remodel the chromatin accessibility landscape. We demonstrated that Zelda preferentially controls expression of the earliest transcribed genes, while genes expressed during widespread activation are predominantly dependent on GAF. Thus, progression through the MZT requires coordination of multiple pioneer-like factors, and we propose that as development proceeds control is gradually transferred from Zelda to GAF.
受精后，生殖细胞的基因组被重新编程以形成全能胚胎。先驱转录因子对于重塑染色质和驱动最初的合子基因表达波至关重要。在这篇论文中，先驱因子 Zelda 对于通过这个称为母源到合子过渡 (MZT) 的剧烈重编程阶段的发育是必不可少的。然而，尚不清楚是否需要其他先驱因子来进行这个过渡。我们鉴定到一个额外的母源编码因子 GAGA 因子 (GAF)，对于通过 MZT 的发育是必需的。GAF 对于激活广泛的合子转录和重塑染色质可及性景观是必需的。我们证明，Zelda 优先控制最早转录基因的表达，而在广泛激活期间表达的基因主要依赖于 GAF。因此，通过 MZT 的进展需要多个先驱样因子的协调，我们提出随着发育的进行，控制逐渐从 Zelda 转移到 GAF。
