In vivo experiments supporting a role for morphogens in axon guidance
| Morphogen pathways . | Genes . | Species . | Experiments . | Phenotypes . | References . |
|---|---|---|---|---|---|
| Hedgehog | Smo | Mouse | Conditional inactivation of Smo in commissural neurons | Commissural axons invade the motor columns | Charron et al., 2003 |
| Shh | Chick | Ectopic expression of Shh in the optic chiasm | Retinal axons are prevented from crossing the chiasm | Trousse et al., 2001 | |
| Shh | Chick | Silencing of Shh by RNA interference | Commissural axons stall at the contraiateral floor plate border, with some axons randomly turning caudally or rostrally | Bourikas et al., 2005 | |
| TGFβ/BMP | Bmp7 and Gdf7 | Mouse | Bmp7 and Gdf7 gene inactivation | Initial trajectory of commissural axons aberrant, axons invade the roof plate | Augsburger et al., 1999; Butler and Dodd, 2003 |
| unc-129 | C. elegans | unc-129 mutation | Defects in the dorsally oriented trajectories of motor axons | Colavita and Culotti, 1998; Colavita et al., 1998 | |
| Wnt | drl | Drosophila | drl mutation | Axons that normally project into the anterior commissure now project into the posterior commissure | Bonkowsky et al., 1999 |
| drl | Drosophila | Ectopic expression of Drl in posterior commissure neurons | Forces posterior commissure neurons to cross in the anterior commissure | Bonkowsky et al., 1999 | |
| wnt5 | Drosophila | wnt5 mutation | Axons that normally project into the anterior commissure project into the posterior commissure | Yoshikawa et al., 2003 | |
| wnt5 | Drosophila | Ectopic expression of Wnt5 throughout the CNS midline | Prevents the anterior commissure from forming | Yoshikawa et al., 2003 | |
| Fz3 | Mouse | Fz3 gene inactivation | Defects in anteroposterior guidance of commissural axons after midline crossing | Lyuksyutova et al., 2003 |
| Morphogen pathways . | Genes . | Species . | Experiments . | Phenotypes . | References . |
|---|---|---|---|---|---|
| Hedgehog | Smo | Mouse | Conditional inactivation of Smo in commissural neurons | Commissural axons invade the motor columns | Charron et al., 2003 |
| Shh | Chick | Ectopic expression of Shh in the optic chiasm | Retinal axons are prevented from crossing the chiasm | Trousse et al., 2001 | |
| Shh | Chick | Silencing of Shh by RNA interference | Commissural axons stall at the contraiateral floor plate border, with some axons randomly turning caudally or rostrally | Bourikas et al., 2005 | |
| TGFβ/BMP | Bmp7 and Gdf7 | Mouse | Bmp7 and Gdf7 gene inactivation | Initial trajectory of commissural axons aberrant, axons invade the roof plate | Augsburger et al., 1999; Butler and Dodd, 2003 |
| unc-129 | C. elegans | unc-129 mutation | Defects in the dorsally oriented trajectories of motor axons | Colavita and Culotti, 1998; Colavita et al., 1998 | |
| Wnt | drl | Drosophila | drl mutation | Axons that normally project into the anterior commissure now project into the posterior commissure | Bonkowsky et al., 1999 |
| drl | Drosophila | Ectopic expression of Drl in posterior commissure neurons | Forces posterior commissure neurons to cross in the anterior commissure | Bonkowsky et al., 1999 | |
| wnt5 | Drosophila | wnt5 mutation | Axons that normally project into the anterior commissure project into the posterior commissure | Yoshikawa et al., 2003 | |
| wnt5 | Drosophila | Ectopic expression of Wnt5 throughout the CNS midline | Prevents the anterior commissure from forming | Yoshikawa et al., 2003 | |
| Fz3 | Mouse | Fz3 gene inactivation | Defects in anteroposterior guidance of commissural axons after midline crossing | Lyuksyutova et al., 2003 |