Investigating cellular aspects of neural progenitor cells in zebrafish forebrain development
In embryonic development, neural progenitor cells (NPCs) that line the neural tube give rise to all neurons and macroglia in the central nervous system (CNS). NPC proliferation needs to be tightly regulated to produce the right number of cells at the right time, as failure to do so can cause embryonic defects such as microcephaly (smaller brains) or megacephaly (bigger brains). Therefore, it is important to understand the cellular and molecular mechanisms that govern NPC behavior in general, and division mode selection in particular. Our aim was to better understand NPC biology in early development using zebrafish as a model system. We present new insights on early forebrain neurogenesis in zebrafish at the whole-tissue level and individual NPC cell biology and transcriptomics in this context. This expands on the previous body of work and provides further grounds for the use of the zebrafish as a model for vertebrate telencephalon development. Furthermore, we develop new tools to study centrosome biology in zebrafish embryogenesis and find that mitotic NPCs in the developing zebrafish forebrain exhibit structural asymmetries. This sets the stage for future studies on the precise role of the centrosome on NPC proliferation and its interaction with other fate determinants. Given the ability of NPCs to generate all types of neurons and macroglia, deciphering the molecular mechanisms that regulate their behavior is key to understanding how, in development, the brain is formed of the correct size and a balanced cellular composition.