During embryonic development, the construction of the nervous system requires the proliferation and the differentiation on billions of neural progenitors cells. We have shown that during early neurogenesis in mouse and chicken embryo models, CDC25B phosphatase, a positive regulator of the G2/M transition, promotes neuronal differentiation (Bonnet et al., 2018) while inducing a shortening of the G2 phase and a lengthening of the G1 phase leading to an unexpected heterogeneity in G1 phase length (Molina et al., 2022).
Our results suggest that CDC25B promote neurogenesis partly through unidentified substrates. One of our aims is to identify these new substrates for the phosphatase CDC25B, using a proximity-based labeling technique allowing protein-protein interaction detection and protein interactome network mapping involved in neurogenesis (coll. Proteomic facility, IPBS Toulouse).
During development, in the spinal cord, progenitor cell modes of division switch from proliferative division to asymmetric neurogenic division and then terminal neurogenic division to generate the appropriate number of neurons. To link cell cycle kinetics and mode of divisions, we have developed mathematical models of motoneurons formation and found two models compatible with spinal neurogenesis at the population levels (Azaïs et al., 2019). We are now refining these models to analyze them at the cell scale. We have generated tree of descend using the two models and showed different outputs that we are now comparing with experimental trees of descent to be able to discriminate which mathematical model recapitulate the best spinal neurogenesis.