The power of our approach lies in the robust comparison of three amniote species. We perform our experiments in the embryos of mouse (Mus musculus), chick (Gallus gallus), and gecko (Paroedura pictus). This range of species represents well the amniote diversity of brains.
In vivo electroporation
We transfect neural stem cells by electroporation of plasmid vectors. This way we introduce the expression of a reporter -usually GFP -or any other type of gene- in progenitor cells and their lineage. This method helps us understand brain development by in utero surgeries for mouse embryos, and in ovo interventions for chick and gecko.
The time during embryonic development when a neuron is generated dictates what neuron it will become. We compare the timing of generation of neurons across brain regions and vertebrate species, aiming to identify conserved and divergent features of brain neurogenesis. Homologous neurons are generated at equal time points on different species, and we study their conserved features.
Viral-mediated lineage analysis
Beyond electroporation, we take advantage of the properties of different viral particles to label the lineage of specific populations of neural stem cells. Retroviral transfections stain the full lineage of infected progenitors. On the other hand, adenoviral transfections only label time-specific populations. These approaches are very useful to research how the lineage of progenitors evolved on amniotes, what is the contribution of each neural sector to the formation of the adult brain.
Single cell RNA sequencing
A major drive of evolution is the evolution of cell types. We investigate the cell types that build the vertebrate brain by single cell RNA sequencing. This powerful method helps us reveal the transcriptome expressed by thousands of individual neural stem cells. By direct comparison of these transcriptomes on our experimental models, our goal is to shed light about the cell composition of the conserved embryonic brain. The understanding of these conserved cells will increase our knowledge on the evolution of the brain.