Whole-gut spatial genomic analysis reveals molecular regionalization of the differentiating zebrafish enteric nervous system
The enteric nervous system (ENS) is the intrinsic nervous system of the gut and controls essential functions, such as gut motility, intestinal barrier function, and water balance. The ENS displays a complex 3D architecture within the context of the gut and specific transcriptional states needed to control gut homeostasis. During development, the ENS develops from enteric neural progenitor cells (ENPs) that migrate into the gut and differentiate into functionally diverse neuron types. Incorrect ENS development can disrupt ENS function and induce various gut disorders, including the congenital disease Hirschsprung disease, or various other functional gut neurological disorders, such as esophageal achalasia. In this study, we used the zebrafish larval model and performed whole gut spatial genomic analysis (SGA) of the differentiating ENS at cellular resolution. To that end, a pipeline was developed that integrated early and late developmental ENS stages by linking various spatial and transcriptional dimensions to discover regionalized cellular groups and their co-expression similarity. We identified 3D networks of intact ENS surrounding the gut and predicted cellular connectivity properties based on the stage. Spatial variable genes, such as hoxb5b, hoxa4a, etv1, and ret, were regionalized along gut axes, suggesting they may have a precise spatiotemporal control of ENS development. The application of SGA to ENS development provides new insights into its cellular transcriptional networks and interactions, and provides a baseline data set to further advance our understanding of gut neurodevelopmental disorders such as Hirschsprung disease and congenital enteric neuropathies.