Clonal analysis of neural progenitors

Resumen

A key question in Developmental Neurobiology is how a pool of progenitors proliferates and differentiates to create an adult brain of appropriate size and cellular composition. So important is the control of the final size, as the proper distribution of cells with different embryonic origins. Each neural progenitor should produce a certain number of neuronal/glial cells encompassing a clone, and all these clones together will result in the adult functional nervous system. The overall goal of this PhD Thesis aimed to develop an in vivo lineage-tracing genetic method to trace all the neural progeny derived from a single cell, UbC-StarTrack. This will allow following cell dispersion of the progeny from embryonic and postnatal mice neural progenitors, independently of their lineage. To validate the method we selected as an experimental system the olfactory bulb, since it is one of the main regions of embryonic and adult neurogenesis. Then, the main experimental approach was based on gene transfection by electroporation with a combination of diverse fluorescent reporter proteins. This produced inheritable marks that enabled the long-term in vivo tracing of the different neural cells from its generation, during embryonic development, to its final fate in the adult brain. First, we analyzed the fate of embryonic progenitors lining either the ventricular surface or the ependymal layer of the olfactory bulbs. Second, we addressed the fate of postnatal progenitors form the dorso-lateral region of the ventricular surface, to finally perform a clonal analysis of newly generated olfactory bulb cells from those postnatal subventricular progenitors. This PhD Thesis will advance the understanding of cell heterogeneity that can be decoded by studying their ontogenetic origin, and could yield to track cell lineages to understand their functional clonal relationships.