Table 3 Short description on ancestral SRGAP2 function
Gene | mRNA expression | Protein expression | Function | Knockout | Knockdown | Overexpression |
|---|---|---|---|---|---|---|
SRGAP2a | ↑ Proliferative zone (VZ and SVZ) ↑ Postmitotic regions (CP) | ↑ throughout cortical development culminating at P1 corresponding to the peak of neuronal migration in the cortex negatively regulate the rate of radial migration by promoting LP branching and dynamics | stage 1 neurons: through its F-BAR domain, induces filopodia stage 2 neurons: ↑ significantly increased the total number of primary neurites emerging from the cell body ↑ increase the number of primary neurite branches | mice are viable (although born significantly below the expected Mendelian ratio) No abnormality in cortical lamination dendritic spine morphology: ↑ neck length ↑ spine density Juvenile: ↓ head width Adult: ↑ head width | ↓ in cortical neurons led to a significant decrease in both axonal and dendritic branching ↑significant increase in the percentage of neurons that have reached the dense CP and a corresponding decreased percentage of neurons in the IZ ↑ accelerated radial migration ↓ LP in layer 5/6 was significantly less branched and less complex dendritic spine morphology: ↑ neck length ↑ spine density Juvenile: ↓ head width Adult: ↑ head width | significantly reduced the number of cells reaching the CP ↓severely inhibited radial migration ↑increase in the percentage of neurons with multiple processes emerging from the cell body – induce excessive branching of radially migrating neurons no transition from multipolar cells to a full LP (no cell body translocation) ↑ spine heads ↓ spine neck ↑ enlargement of dendritic spines |