Primate-specific gene TMEM14B promotes cortical expansion and folding

A massively expanded outer subventricular zone (OSVZ) in the primate and human has been proposed for generating majority of neocortical neurons, which consists of basally located radial glia cells. Previous studies with various strategies have tried to recognize genes specifically expressed in those cells; however, the molecular and cellular features of these cells still remain uncertain. By profiling gene expression across single cells isolated from cellular anatomy location and subtype sorting, we identified a primate-specific gene TMEM14B as a novel marker for basally located radial glia. Expression of TMEM14B induced dramatic increase in the number of radial glial and OSVZ region. Finally, we found that OSVZ progenitor's extensive proliferative potential was up regulated through IQGAP1 phosphorylation and nuclear translocation, and remarkably, led to the gyrification in postnatal mouse. These results highlight that evolutionary expansion promoted by primate-specific genes enabling the evolutionary expansion and folding of the human neocortex. Overall design: Find specific markers from dataset of 4 different types of cells