A conserved logic for the development of cortical layering in tetrapods [St_30-53]

We find that the salamander dorsal pallium is layered: superficial and deep-layer neurons have distinct birthdates, transcriptomic identities and projections. Using lineage tracing and scRNA-seq, we uncover evolutionarily-conserved principles of cortical development, including temporal patterning in multipotent radial glia progenitors, and the deployment of intermediate progenitor cells.

We also describe the transcriptomic divergence of neuronal differentiation programs across species, suggesting that evolutionary diversification of cortical neuron types stems from changes in gene regulation after cell cycle exit. Our findings challenge long-held assumptions on the development and evolution of the cerebral cortex, and suggest that the mammalian neocortex evolved through modifications of a conserved developmental framework.