Fig. 6

Expression of met receptor and hgf1 and hgf2 ligand in the facial motor neurons (FMNs). (A–C) Dorsal view and (A′–C′) transverse views at the level of r5 in the hindbrain of 33 hpf embryos showing mRNA expression of met receptor (A and A′), hgf1 ligand (B and B′) and hgf2 ligand (C and C′). met receptor is expressed in the migratory FMNs (arrows in A and A′) in the ventral hindbrain, while hgf1 and hgf2 ligands are expressed in ventral tissues surrounding the hindbrain in regions where FMNs migrate towards the posterior hindbrain (arrows in B′ and C′, respectively). In addition, hgf1 and hgf2 ligands are expressed in pharyngeal arches, ventrolateral to the hindbrain (arrows in B and B′ and C and C′, respectively). White lines in (A)–(C) indicate the position at which transverse sections were obtained (A′–C′). (D–F) Dorsal confocal sections of 48 hpf Islet1-GFP embryos in the hindbrain regions showing colocalization (in F) of met mRNA (E) with GFP antibody in green (D) in the VII nerve and in the X nerve. White arrows in (F) indicate the presence of met transcripts in other population of hindbrain cells. (G–I) Dorsal confocal sections of 48 hpf Isl1-GFP embryos in the hindbrain regions double stained with GFP antibody in green (G) and Zn5 antibody, which recognizes zebrafish DM-GRASP, a cell adhesion molecule, in red (H) in the abducens motor neurons (VI nerve). Colocalization of GFP and Zn5 antibodies (in I) identifies the population of met-positive neurons as the abducens motor neurons; neurons also indicated by white arrows in (F) and (I). FMNs, facial motor neurons; V, trigeminal motor neurons of the V nerve; VII, facial motor neurons of the VII nerve; X, vagal motor neurons of the X nerve; VI, abducens motor neurons of the VI nerve. Scale bar, 50 μm.