Sox3 knock-down causes reduced neural tissue in the CNS. (A–C) In situ hybridisation of 24 hpf embryos showing the expression of the neural markers sox2 (A, B) and ncad (C). (A) Lateral views. (B, C) Dorsal views. Embryos injected with mis-match control MOs (mmMOs) are indistinguishable from wild-type (Ai, Bi, Gi). Injection of sox3MOs causes severe loss of neural structures in the brain and loss of caudal tissues (Aii: 25/307, Aiii: 135/307, Aiv: 67/307) and the remaining neural tissue of the head is disorganised but continues to express sox2 (Bii) and ncad (Cii) strongly. The MO phenotype is rescued by co-injection with sox3 mRNA (Aiii, Biii, Ciii: 91/113). (D, E) Transverse sections cut in the midbrain (D) and hindbrain (E) viewed under white light (Di, Dii, Ei, Eii) or DAPI stain (Diii, Div, Eiii, Eiv) showing loss of lumen (indicated by asterisk, Diii, iv) and reduced hindbrain (roof plate indicated by arrow, Ei, ii) in sox3 morphant embryos. (F) Transverse section cut of the spinal cord of control (Fi–iii) or morphant (Fiv–vi) embryos viewed under white light (Fi, ii, iv, v) or DAPI stain (Fiii, iv). (Fi, iv) Lateral view of embryos showing position where sections were taken. Scale bars are equal to 100 μm (Di, Ei) or 50 μm (Fii). (G) Fluorescent images of TUNEL stained 24 hpf embryos, lateral views. Significant fluorescent signal in morphant embryos (Gii, 11/11 compares to phenotype in Aiii) shows increased apoptosis compared to wild-type controls (Gi). MO-induced apoptosis is rescued by co-injection with sox3 mRNA (Giii, 11/13). Position of the brain is marked by asterisks and the arrows indicate ventral edge of the tail in wild-type and rescue embryos (Gi, iii).
|
