Fig. 7

sid4 s-mo causes defects in local patterning of branchiomotor neurons and cranial neural crest development without altering early anteroposterior patterning of the brain. (A) The pattern of pax-2 expression is normal in eye primordia, midbrain hindbrain boundary, and otic vesicles of both control and (B) morphant embryos, although the number of pax-2 cells within each expression domain of morphants appears reduced. (C–F) The AP pattern of krox20 expression in rhombomeres 3 and 5 and in migrating neural crest (white arrow) is unaffected in controls (C) and morphants (D–F). (E, F) Rhombomeres are broadened and boundaries more diffuse in morphants. (G) Branchiomotor neuron patterning is normal in control embryos but increasingly disorganized in (H) mildly affected and (I) caudally truncated embryos. (J) Normal migration of pigmented, non-retinal epithelium over the eyes of 48 hpf control embryos. (K) Pigment cells are concentrated in the dorsal portion of the eye in morphants (red arrow) and fail to migrate ventrally. (L) Normal forebrain expression of dlx-2 in 24 hpf control embryos. (M) Diencephalic, dlx-2 expressing neural crest cells are reduced or absent in morphants. This phenotype does not recover in 31 hpf embryos (insets in L, M). Dorsal views in A–I. Lateral views in J–M. Anterior is to the left in all panels. Embryos in J and K were fixed and cleared in glycerol. The right eye was removed and the left eye shown in both panels. d, diencephalon; e, eye; mhb, midbrain hindbrain boundary; ov, otic vesicle; t, telencephalon. In situ probes are indicated in the lower right of each panel.