The disconnect2 mutation disrupts the tjp1b gene that is required for electrical synapse formation

To investigate electrical synapse formation in vivo we used forward genetics to disrupt genes affecting Mauthner cell electrical synapses in larval zebrafish. We identify the disconnect2 (dis2) mutation for its failure to localize neural gap junction channels at electrical synapses. We mapped this mutation to chromosome 25 and identified a splice-altering mutation in the tjp1b gene. We demonstrated that the dis2 mutation disrupts tjp1b function using complementation analysis with CRISPR generated mutants. We conclude that the dis2 mutation disrupts the tjp1b gene that is required for electrical synapse formation. DescriptionNeural networks are circuits of neurons wired together during development that provide an animal with specialized behavioral outputs. Dedicated adhesions called neuronal synapses create sites of communication between neurons and can be categorized as either electrical or chemical. This work identifies a new mutation in tjp1b that is shown to be required for electrical synapse formation.