Hominid-specific transposable elements and KRAB-ZFPs facilitate human embryonic genome activation and transcription in naïve hESCs [ATAC-seq]

Transposable elements (TEs) are key to the evolutionary turnover of regulatory sequences. How they can play such an essential role in spite of their genotoxic potential is unknown. Here, we demonstrate that KRABcontaining zinc finger proteins control the timely and pleiotropic engagement of TE-derived cis-regulators of transcription. We first observed that evolutionary recent TEs of the SVA, HERVK and HERVH subgroups are major contributors to chromatin opening during human embryonic genome activation and act as KLF-stimulated enhancers in naïve embryonic stem cells. We then found that KZFPs of corresponding evolutionary ages are simultaneously induced and repress the transcriptional activity of these TEs. We finally determined that the same KZFP-controlled TE-based enhancers later serve as developmental and tissue-specific regulators of gene expression. Thus, by taming the transcriptional impact of TEs during early embryogenesis, KZFPs allow for their genome-wide incorporation into transcriptional networks, thereby contributing to the species-specificity of human genome regulation. ATAC-seq was performed on primed WIRB3 and WIBR3dPE; naïve WIBR3 and WIBR3dPE in 4iLA and KN/2iL media respectively; and in WIBR3dPE in KN/2iL media upon dCAS9-KRAB overexpression containing or not a guide RNA targeting SVA/LTR5Hs