Figure 7. Transcription factor profiles register the developmental history and contribute to maintenance of PCP phenotypes.

(A) Schematic developmental trajectory of cortical GABAergic neurons (PVBC as example), with TFs expressed at different stages.

(B) Schematic of MGE and CGE transcription cascades that regulate the development of different clades of GABAergic neurons, including PCPs

(C) Each PCP is estimated to express ~400 TFs.

(D–G) Fraction of cells expressing a given TF (10% of max level); boxplots show expression levels of selected TFs. (D) TFs in subpallium progenitors and GABA neuron precursors maintain their expression in PCPs in adult.

(E) TFs expressed in early postmitotic MGE- and CGE- derived neurons maintain expression within same clade of PCPs. Embryonic expression of Tox and Nfi family TFs were deduced from transcriptome analysis of PCPs and confirmed in (I).

(F) Among MGE-derived PCPs, subsets of TFs are preferentially expressed in PV (PV>SST) or SST (PV<SST) groups; CGE groups are not compared and shown in light shade; selected boxplots are shown.

(G) Within the PV, SST and VIP group, subsets of TFs are enriched in one or the other PCP; PCPs that are not compared are shown in light shade.

(H) DE of TFs is largely exclusive to each PCP (left); examples of ON/OFF expression in individual PCPs (right).

(I) Retrospective screen of Allen Developmental Mouse Brain in-situ database reveals that several TFs that express in MGE- or CGE- derived PCPs identified by transcriptome analysis indeed begin their expression in the corresponding embryonic germinal zone.

(J) Schematic of the Ppargc1α (PGC1α) transcription regulatory network highly enhanced in PVBCs. Multiple PGC1α upstream TFs activators, cofactors and large fraction of (>75%) of downstream effectors are enriched over 1.5 folds in PVBCs (p<5.0^−07). Boxplots show different expression levels of select sets of PGC1α co-factors and targets and putative targets among PCPs.

Also see also Figure S7.