Ciliogenesis defects after neurulation impact brain development and neuronal activity in larval zebrafish

Cilia are slender, hair-like structures extending from cell surfaces and playing essential roles in diverse physiological processes. Within the nervous system, primary cilia contribute to signaling and sensory perception, while motile cilia facilitate cerebrospinal fluid flow. Here, we investigated the impact of ciliary loss on neural circuit development using a zebrafish line displaying ciliogenesis defects. We found that cilia defects after neurulation affects neurogenesis and brain morphology, especially in the cerebellum, and lead to altered gene expression profiles. Using whole brain calcium imaging, we measured reduced light-evoked and spontaneous neuronal activity in all brain regions. By shedding light on the intricate role of cilia in neural circuit formation and function in the zebrafish, our work highlights their evolutionary conserved role in the brain and set the stage for future analysis of ciliopathy models. To analyse the impact of cilia loss on gene expression, we performed RNA sequencing analysis of 4 days old elipsa mutant and sibling control zebrafish larvae. We extracted total RNA from mutant (selected based on their curly tail down phenotype) and sibling controls (mixture of heterozygous and wild-type). RNAsequencing was performed on 4 different clutches.