show Abstracthide AbstractThe work associated to these datasets focuses on the investigation of transcriptional regulation during the earliest stages of mammalian embryogenesis. In particular, ChILseq and RNAseq datasets were generated to study the process of zygotic genome activation in mouse embryos. After fertilisation, the mouse embryo activates its own genome for the first time in a process known as zygotic genome activation, which occurs primarily on two main waves. The first wave occurs in zygotes, and the second one at the late 2-cell stage. To understand how the RNA Polymerase II functions during these waves, we have implemented a ChILseq approach to generate genome-wide maps of Ser5 and Ser2 phosphorylated forms of RNA Polymerase II in zygotes, 2- and 8-cell stage embryos. In addition, we have investigated how elongation factors, such as NELF and DSIF regulate major ZGA by performing single embryo RNAseq using SMART-seq2 in 2-cell stage embryos upon depletion of Spt5, NELFE and upon chemical inhibition of Cdk9. Overall design: RNA-seq experiments upon Cdk9 inhibition, Spt5, NELF-E depletion by Trim-Away as well as IgG Trim-Away and no injection control in single 2-cell stage embryos.