Toolkit development for identification of GABAergic neuronal subpopulation and conditional control of ectopic gene expression

Abstract

The hindbrain is the most posterior part of the vertebrate brain. This evolutionarily ancient region contains distinct progenitor cell populations that will give rise to different neuronal identities. Neurogenesis starts with the expression of proneural genes, which commit cells to the neuronal lineage and activates the differentiation pathway. However, the mechanism of how proneural genes can influence neuronal differentiation remains unclear. In this study, we developed two tools to investigate how proneural genes are regulated to trigger neuronal differentiation, focusing on the zebrafish hindbrain. First, since we are interested in GABAergic neurons, we aimed to investigate the potential of homeodomain transcription factors as putative markers by gene expression. Our findings indicate that gata3 and dbx1a exhibit specific expression patterns in mediodorsal regions at 76 hours postfertilization. Second, we designed a system to enable the ectopic gene expression in specific neuronal progenitors, allowing for conditional control of gene expression together with cell tracing. Our results indicate the correct obtention of two out of three plasmids needed. To sum up, we generated useful tools that will contribute to the understanding how proneural genes regulate differentiation.