研究実績の概要 |
This project elucidated the role of Neurexins (Nrxns) in the early evolution of the nervous system. Nrxns are core presynaptic cell adhesion molecules with critical functions in the chemical synapse, but their origin and evolutionary history remain underexplored. I employed a multidisciplinary approach to give the first characterization of Nrxn-mediated neuronal signaling outside Bilateria. I showed that in Nematostella vectensis, a member of Cnidaria which is the closest outgroup to Bilateria, knocking down the neuronally expressed Nrxns resulted in abnormal behaviors involving muscle contraction. I demonstrated that the neural Nrxns in N. vectensis are required for the transmission of classical chemical transmitters (e.g., glutamate, glycine) but not for neuropeptide signaling. Additionally, a non-neural function of N. vectensis Nrxns was that may explain how and why this family of proteins was employed in the synaptic machinery of the early nervous system. Functional analysis of the broadly expressed Nrxns in N. vectensis revealed their major role in heterologous cell-cell adhesion; in particular, in the maintenance of the junction between ectodermal and endodermal epithelial cells. I have completed all the experiments by the end of FY2021. In FY2022 (April to October), I performed additional experiments for the manuscript that is being prepared for submission.
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