each NGN2-iN cluster with PNS and CNS neurons from primary reference cell atlases (Clark et al., 2019; La Manno et al., 2020; Zeisel et al., 2018) (Figure 3C). Unlike neurons in the iPSC-derived cerebral and retinal organoids, the NGN2-iN clusters did not show specific transcriptomic similarity to any CNS neuron subtypes (Figures 3C and S4D). Some NGN2-iN clusters were relatively similar to PNS neurons, especially the PRPH+ clusters, although they did not specify any of the PNS neuron subtypes. We explored if NGN2-iN expressed markers of primary neuron subtypes (Figures 3D and S4E). There is no clear in vivo neuron population as the counterpart of any NGN2-iN cluster. We deconvoluted the ratio of PNS/CNS identity for each cluster and found that all NGN2-iNs have mixed signatures of CNS- and PNS-derived neurons without a clearly established identity (Figure 3E). We find that the GPM6A+ cluster has more CNS features while the PRPH+ clusters have a biased PNS signature, in line with GPM6A and PRPH showing high expression in CNS and PNS neurons, respectively. Altogether, our data suggested that NGN2-iNs have a mixture of neuronal signatures, and we were not able to establish a clear identity of NGN2-iN populations. We note that
