student Guangzhou National Laboratory Guangzhou, Guangdong, China (People's Republic)
Abstract: During mammalian embryogenesis, temporal and spatial regulation of gene expression and cell signaling influences lineage specification, the patterning of tissue progenitors and the morphogenesis of embryo. Gastrulation and organogenesis are the processes that the cells of the three germ layers transform into an embryo that includes most of the major internal and external organs within a short timeframe. In previous research, we have reconstructed the molecular trajectory of the gastrulating embryos. Here, we performed Geo-seq+ technology to reconstruct a spatial molecular atlas encompassing embryonic and extraembryonic tissues in mice, ranging from the egg cylinder (E5.5) to the early stage of organogenesis (E8.75), at 6-hour intervals for a total of 14 stages. This spatiotemporal transcriptome provides genome-wide digitized gene expression profiles at the resolution of a few cells and defines the molecular characteristics of the genealogy of lineages and continuum of organic primordium in time and space. Remarkably, we systematically revealed the molecular regulatory network of patterning along the anterior-posterior and dorsal-ventral axes during endodermal organogenesis and uncovered interactions between the splanchnic mesoderm and gut endoderm during their differentiation into various organ primordia. Our findings shed light on the spatial patterning of axes, the systematic temporal regulation of developmental progression, and the spatial interactions among inter-germ layer lineages that orchestrate gut organogenesis, providing insights into the intricate mechanisms underlying organogenesis.
