TABLE 1.
List of genes involved in bRG generation.
| Gene/Protein | Function | Model | Manipulation | Effect(s) on progenitors | Cell mechanism described | Other phenotype(s) described |
| ARHGAP11B | ? | Mouse (IUE+mRNA microinjection) | Expression | IPs↗, basal mitoses↗ | Cell fate change in aRG to produce more BPs, Proliferation↗ | Thicker SVZ, Cortical folds, cortical expansion |
| Ferret (IUE) | Expression | IPs↘, bRGs↗ | Oblique/horizontal division in aRGs, Proliferation↗ | Cortical expansion, upper-layer neurons↗ | ||
| Aspm | MT associated protein | Ferret (transgenic line) | KO | bRGs↗ | Early delamination of aRGs | Thinner VZ, microcephaly with conserved cortical layers |
| Mouse (transgenic line) | KO | ? | Mislocalized centrosomes and aberrant ventricular lining | – | ||
| Cdh1 | Cell adhesion molecule | Ferret (IUE) | Expression of dominant-negative form | aRGs↘, bRGs↗ | Cell adhesion↘, Oblique/horizontal division in aRGs | – |
| FGFR1, MEK, ERK, ETV4 | RTK, MAPK, TF | Mouse (IUE) | Pathway activation (constitutively active form of FGFR1, Mek, Etv4) | bRGs↗ | Proliferation↗ | Upper-layer neurons↗ |
| FGFRs | RTK | Ferret (IUE) | Pathway inhibition | bRGs↘ | Proliferation↘ in bRGs | Loss of cortical folds |
| GPSM2 (LGN) | Regulator of mitotic apparatus | Mouse (IUE/transgenic line) | Expression of dominant-negative form | bRGs↗ | Oblique/horizontal division in aRGs | – |
| Hif1α | TF | Mouse | Regulation of the pathway (Hyperoxia during pregnancy) | IPs↗, bRGs↗ | ? | OSVZ-like region |
| INSM1 | TF | Mouse (IUE) | Overexpression | IPs↗ in the VZ, bRGs↗ | Cell detachment from VZ, disruption of adherens junctions | – |
| Pax6 | TF | Mouse (IUE/transgenic line) | Forced expression in BPs | IPs↘, bRGs↗ | Oblique/horizontal division in aRGs, Proliferation↗ | OSVZ-like region, thicker cortex, upper-layer neurons↗ |
| Mouse (transgenic line) | KO | bRGs↗ | Cell adhesion↘, mostly non-cell autonomous | – | ||
| PDGFD/PDGFR signaling | PDGF receptor/ligand | Human brain slices | Pathway inhibition (treatment with PDGFRβ inhibitor) | IPs↘, bRGs↘ | ? | – |
| Mouse (IUE+PDGF-DD injection) | Expression (constitutively active form of PDGFRβ)/Pathway activation | bRGs↗ | ||||
| PTEN | Phosphatase | Human organoids | Pathway activation (CRISPR/Cas9 targeting of PTEN) | bRGs↗ | ? | Increased volume and cortical folds |
| Mouse organoids | ? | Increased volume but no cortical folds | ||||
| SMARCC1 (Baf155) | Chromatin remodeling factor | Mouse (IUE/transgenic line) | KO | IPs↘ (ectopic IPs in IZ), bRGs↗ | Oblique/horizontal division in aRGs, regulates Pax6, cell adhesion↘ | - |
| SmoM2 | Shh pathway activator | Mouse (transgenic line) | Pathway activation (constitutively active form of SmoM2) | IPs↗, bRGs↗ | Proliferation↗ | Cortical folds, brain expansion |
| TBC1D3 | RABGAP | Mouse (IUE/transgenic line) | Expression | aRGs↗, IPs↗, bRGs↗ | Cell adhesion↘, proliferation↗ | Cortical folds |
| Human brain slices (electroporation) | KD | bRGs↘ | ? | – | ||
| TMEM14B | Kinase? | Mouse (IUE) | Expression | IPs↗, bRGs↗ | Oblique/horizontal division in aRGs, Proliferation↗ | OSVZ-like region, cortical folds |
| Trnp1 | TF | Mouse (IUE) | KD | aRGs↘, IPs↗, bRGs↗ | Cell adhesion? | Cortical folds |
In this table are indicated the genes, their function, the model in which they were tested, the type of experiment performed, the effect on progenitor cells, the cellular mechanisms indicated in each study and other phenotypes associated with bRG regulation. IUE, in utero electroporation; aRGs↘, IPs↘, bRGs↘, diminution of the proportion of aRGs, IPs, and/or bRGs; aRGs↗, IPs↗, and bRGs↗, increase of the proportion of aRGs, IPs, and/or bRGs; Cell adhesion↘, diminution of cell adhesion (generally associated with loss or diminution of expression of adherens junction proteins or other cell adhesion molecules). Proliferation↗, increase in the proportion of mitotic and/or cycling cells; upper-layer neurons↗, increase in the proportion of upper-layer neurons in the cortical plate.