We then aimed to demonstrate the suitability of the OPTiKD platforms to investigate the function of genes that are not only expressed during early development, but also in differentiated cells. We focused on DPY30, a ubiquitously expressed co-factor of the COMPASS histone methyltransferase complexes required for histone H3 lysine 4 trimethylation (H3K4me3) (Jiang et al., 2011). This epigenetic modifier is necessary for mouse early embryonic development, as its knockout leads to impaired gastrulation associated with ectopic neuralization of the post-implantation epiblast (Bertero et al., 2015). Similarly, DPY30 is required for hESC pluripotency (Bertero et al., 2015), and this early role had prevented further studies of its function during differentiation. Finally, Dpy30 has been implicated in mouse ESC differentiation and in the proliferation and differentiation of hematopoietic progenitors (Jiang et al., 2011; Yang et al., 2014). Consequently, we decided to employ our inducible knockdown platform to bypass the early function of DPY30 in hPSCs and specifically suppress its expression during differentiation (Fig. 6A).
