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Fig. 2
The development of the CNS and somites is impaired in Neogenin knockdown embryos (morphants). Neogenin morphants (b, d, and f) were generated using a neogenin antisense morpholino oligonucleotide (ATG-MO; 3.7 ng). Controls (a, c, and e) were generated using a control morpholino oligonucleotide (CONT-MO; 3.7 ng). (a) Normal somite (so) development at the 10 somite stage (14 hpf) in embryos injected with CONT-MO. (b) Somites of the ATG-MO-injected embryos were thinner along the rostrocaudal axis and wider along the mediolateral axis. (c) At 24 hpf, key structures of the early CNS such as the midbrain-hindbrain boundary (mhb), tectal ventricle (tv), fourth ventricle (iv), tegmentum (tg), and cerebellum (ce) were precisely delineated in embryos injected with CONT-MO while (d) ATG-MO-injected embryos exhibited severe perturbations in the development of these CNS structures. (e) 36 hpf embryos injected with CONT-MO showed no gross morphological abnormalities. (f) By 36 hpf, the rostrocaudal body axis of the morphants was shorter than that of control embryos. The length of the dorsoventral axis of the developing brain was reduced in morphants, indicated by the reduced length of the horizontal bar (inset) compared to controls, suggesting a loss of neural tissue. d, Diencephalon; hb, hindbrain; nc, notochord. (a and b) Dorsal views with rostral to the top. (c-f) Lateral views with rostral to the left and dorsal to the top.
Reprinted from Developmental Biology, 269(1), Mawdsley, D.J., Cooper, H.M., Hogan, B.M., Cody, S.H., Lieschke, G.J., and Heath, J.K., The Netrin receptor Neogenin is required for neural tube formation and somitogenesis in zebrafish, 302-315, Copyright (2004) with permission from Elsevier. Full text @ Dev. Biol.