Growth of the RP processes correlates with a shift of <i>glyt1</i> expression along D–V axis.

<p>(A–D), Double whole mount <i>in situ</i> hybridization (<i>glyt1</i>, dark purple) and immunostaining (GFP, green). <i>glyt1</i> is expressed in the midline glial cells except RP; GFP is expressed in the RP cells. (E–J), Whole mount <i>in situ</i> hybridization (<i>glyt1</i>, dark purple) and immunostaining (β-catenin, red), the transverse sections of the spinal cord. The arrow shows an approximate position of attachment of the RP process to the apical surface of central canal. Confocal images of the spinal cord of <i>pard6γb</i> heterozygote (K) and <i>pard6γb</i> mutant (L) transgenic fish. (M), double whole mount <i>in situ</i> hybridization (<i>glyt1</i>, dark purple) and immunostaining (GFP, green) of <i>pard6γb</i> mutant. Abbreviation: fp, floor plate.