Table 2.
Summary of the defects reported by studies on different Arx mutant lines. The percentages of cells are expressed by comparison to the number of cells in wild-type mice.
| Tangential migration from MGE to ctx (Kitamura et al., 2009) | Arx KO | E12.5: no initiation of migration | E14.5: stream only in the SVZ | P0: 28.5% ARX+ in CP |
| Arx P353R | E12.5: Initiation of migration | E14.5: stream only in the SVZ | P0: no ARX+ in CP | |
| Arx P353L | E12.5: Initiation of migration | E14.5: streams OK | P0: 92.8% ARX+ in CP | |
| Arx(GCG) + 7 | E12.5: no initiation of migration | E14.5: streams OK | P0: 88.4% ARX+ in CP | |
| Radial + tangential migration in striatum (P0) (Kitamura et al., 2009) | Arx KO | Thickened SVZ in striatum | Defect in radial migration | |
| Loss of GABAergic interneurons in striatum | Defect in tangential migration | |||
| ArxP353R | VZ + SVZ thicker (ARX+/MAP2−) | Defect in radial migration | ||
| Accumulation of SST+ cells in SVZ of ventral striatum, No SST cell in the | Defect in tangential migration | |||
| mantle zone of the striatum | Normal radial migration | |||
| Arx P353L | No increase in VZ/SVZ thickness | Defect in tangential migration | ||
| ↓ Number of SST+ cells in the mantle zone of the striatum | Normal radial migration | |||
| Arx(GCG) + 7 | No increase in VZ/SVZ thickness | Defect in tangential migration | ||
| Most of SST+ cells visible in the VZ of the striatum | ||||
| Radial migration in ctx (P0) (Kitamura et al., 2009) | Arx KO | Thinner CP without severe abnormal structure | Defect in radial migration | |
| Arx P353R | Tbr1+ deep layer a bit bigger, | Defect in radial migration | ||
| Foxp1+ middle layer abnormal, | ||||
| Satb2+ upper layer thinner | ||||
| Arx P353L | No difference with wild-type | Normal radial migration | ||
| Arx (GCG) + 7 | No difference with wild-type | Normal radial migration | ||
| Cholinergic neuron differentiation (Kitamura et al., 2009; Price et al., 2009) | Arx KO | No ChAT+ cells in the forebrain | ||
| Arx P353R | No Lhx8 expression at P0 | |||
| Arx P353L | Slight ↓ of Lhx8 expression | |||
| Arx (GCG) + 7 | No Lhx8 expression at P0 | |||
| Severe loss of ChAT+ cells in basal ganglia, 39% in striatum | ||||
| Somatosensory cortex | Striatum | |||
| ↓ of GABAergic neurons (4–6 weeks post-natal) (Kitamura et al., 2009; Marsh et al., 2009; Price et al., 2009) | Arx KO | Absence of NPY+ cells | Loss of NPY+ cells | |
| ↓↓ in CB+ cells | ||||
| ↓CR+ cells | ||||
| No change in PV+ cells | ||||
| Arx P353L | 92.7% GAD67+ | 45% NOS+ | ||
| 74% SST+ | 47.8% SST+ | |||
| 100% NPY+ | 60% MPY+ | |||
| 100% PV+ | 85.2% PV+ | |||
| Arx (GCG) + 7 | 87.5% GAD67+ | 45% NOS+ | ||
| 100% SST+ | 52.4% SST+ | |||
| 100% NPY+ | 60–69% NPY+ | |||
| 81–100% PV+ | 70.6% PV+ | |||
| 100% CR+ | ||||
| 58% CB+ | 47% CB+ | |||
| 58–100%ARX+ | ||||
Ctx, cortex; KO, knock-out; SST, somatostatin; VZ, ventricular zone; SVZ, subventricular zone; CP, cortical plate; ChAT, choline acetyltransferase; CB, calbindin; CR, calretinin; PV, parvalbumin; NOS, nitric oxide synthase.