TY - JOUR TI - ME31B globally represses maternal mRNAs by two distinct mechanisms during the Drosophila maternal-to-zygotic transition AU - Wang, Miranda AU - Ly, Michael AU - Lugowski, Andrew AU - Laver, John D AU - Lipshitz, Howard D AU - Smibert, Craig A AU - Rissland, Olivia S A2 - Green, Rachel VL - 6 PY - 2017 DA - 2017/09/06 SP - e27891 C1 - eLife 2017;6:e27891 DO - 10.7554/eLife.27891 UR - https://doi.org/10.7554/eLife.27891 AB - In animal embryos, control of development is passed from exclusively maternal gene products to those encoded by the embryonic genome in a process referred to as the maternal-to-zygotic transition (MZT). We show that the RNA-binding protein, ME31B, binds to and represses the expression of thousands of maternal mRNAs during the Drosophila MZT. However, ME31B carries out repression in different ways during different phases of the MZT. Early, it represses translation while, later, its binding leads to mRNA destruction, most likely as a consequence of translational repression in the context of robust mRNA decay. In a process dependent on the PNG kinase, levels of ME31B and its partners, Cup and Trailer Hitch (TRAL), decrease by over 10-fold during the MZT, leading to a change in the composition of mRNA–protein complexes. We propose that ME31B is a global repressor whose regulatory impact changes based on its biological context. KW - maternal-to-zygotic transition KW - ME31B/DDX6 KW - mRNA decay KW - translation JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -