Characterization of Zebrafish Lateral Line Cell Type Heterogeneity Between Development and Regeneration

Abstract

Mammalian inner ear hair cells fail to regenerate once damaged, but other vertebrates such as zebrafish and chick, have the ability to restore lost hair cells. Understanding the developmental and regenerative programs of sensory hair cells in these species is crucial to develop therapeutic strategies that will ultimately help to restore hearing in humans. In this study, we characterized the development and regeneration of zebrafish lateral line sensory hair cells, which readily regenerate after ablation. To distinguish cluster identities in the primordium at the early stage of development, I characterized the cluster identities of primordium at 24 hpf using HCR and found distinct cell types within the zebrafish lateral line system, which includes hair cells, hair cell progenitors, neuromast, leading edge of primordium, trailing edge of primordium, mid-primordium region, mitotic cells, otic neuromast, supraorbital primordium and infraorbital primordium . We further aimed to shed light on the Notch/delta signalling pathways governing hair cell development and regeneration of the neuromast. Loss of the Delta ligand dll4 led proliferation during regeneration of hair cells in neuromast. Further, we investigated the potential downstream targets impacted by the loss of the dll4.