S3 for complete list of differentially expressed genes). We plotted the top 50 DEX genes ranked by test significance (Figure 6A), and the 29 genes enriched in maturing SST cells includes a number of genes implicated in migration (DAB1, CNTNAP2, PHLDA1), synaptogenesis (SERPINI1, NTM, OPCML) and axon outgrowth (CNTN1, DCC), as well as three immunoglobin superfamily genes (CNTN1, OPCML and NTM). GABA receptors, ion channels and proteins that directly regulate ion channel function are also prominent features (RIC3, GABBR2, GABRG2, SCN2A, KCNC2). RAB3B is a small GTP-binding protein known to modulate synaptic release, but it has not been implicated in interneuron differentiation or function to date (Schluter et al., 2006). These results emphasize the fact that transcriptomic changes occurring during neuronal differentiation can be observed in vitro using single-cell and computational methods, providing a means to identify processes that affect brain development and function in specific ways.
