The dynamic expression pattern of signaling pathways involved in early embryo development.

Early embryonic development in mammals involves extensive intercellular communication and interaction. The rapidly changing signaling pathways, governed by signaling pathway-related genes (SPGs), underlie these intricate communication networks and mediate a series of developmental events, including blastulation and gastrulation. However, the detailed expression patterns of SPGs remain to be clearly illustrated. In this study, we used mouse and human transcriptomic and epigenomic data to systematically depict the dynamics of signaling pathway networks during early embryonic development. Our results indicate that zygotic genome activation (ZGA) triggers considerable remodeling of SPGs transcriptional patterns, which coincides with noticeably elevated promoter accessibility after ZGA in both humans and mice. In addition, most SPGs are maternally inherited and are more conserved between humans and mice compared to those activated by the zygotic genome. Interestingly, we found that various extracellular matrix (ECM)-related signaling pathways were highly enriched during early embryogenesis. Two enriched and conserved receptors in several ECM-related pathways, SDC1 and SDC4, were expressed on the cell membrane from oocyte to blastocyst stage both in humans and mice. Knockdown of Sdc1 and Sdc4 in mice resulted in an impaired developmental rate from the 8-cell stage via different mechanisms. Collectively, our study provides new insights into understanding the underlying mechanisms of early embryo development.