Transcriptional profile of SAG neurod+ neuroblasts from clo mutant and sibling embryos at 54 hpf

In many organs, stem cell function depends on the communication with their niche partners. Cranial sensory neurons develop in close proximity to blood vessels, however whether vasculature is an integral component of their niches is yet unknown. Here, two separate, novel roles for vasculature in cranial sensory neurogenesis in zebrafish are uncovered. The first involves a restrain of neuroblast proliferation at early stages. The second instead, requires blood flow to trigger a transcriptional response, which has been identified thanks to a RNAseq analysis. This transcriptional change modifies neuroblast metabolic status and induces sensory neuron differentiation. Altogether, we demonstrate that the cranial vasculature constitutes a hitherto unrecognized niche component of the sensory ganglia that regulates the pace of their growth and differentiation dynamics.