nr2f5 Misexpression Reduces and Transforms the Lower Jaw
(A–G) Alcian blue and alizarin red staining of dissected facial skeletons shown from the ventral perspective. The upper jaw (Ptp, green in A′–C′) remains, but the lower jaw (M, magenta in A′) is reduced and transformed (black arrows) in sox10:Gal4VP16; UAS:Nr2f5el662 transgenic fish (B), similar to edn1 mutants (C). Putative transformations are schematized in (A′–C′). Late-onset nr2f5 misexpression in chondrocytes (col2a1a:Gal4VP16) did not affect the facial skeleton (D). Misexpression in post-migratory mandibular NCCs (hand2:Gal4VP16) reduced the distal tips of Meckel's (black arrow, E). Heat-shock-induced embryo-wide misexpression (hsp70l:Gal4) reduced the lower jaw (black arrow) when applied at 15–17 (F) but not 19–21 hpf (G).
(H) Approximate timing of Nr2f5 protein overexpression (OE) in the different driver lines, with the approximate window of sufficiency indicated in magenta.
Scale bar, 50 μm. Also see Figure S3 for additional analyses of the sox10:Gal4VP16; UAS:Nr2f5 phenotype.