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. Author manuscript; available in PMC: 2010 Nov 24.
Published in final edited form as: Dev Biol. 2009 Jan 15;325(2):363–373. doi: 10.1016/j.ydbio.2008.10.030

Fig. 4.

Fig. 4

Neuronal defects in tag1 morphants. Panels A, B, E–J show dorsal views of the head with anterior to the left (anterior at top in G, H). Panels C, D, K and L show lateral views of the head with anterior to the left. tag1 morphants (D, F, and H) were co-injected with p53 MO to minimize non-specific apoptosis (Robu et al., 2007). WT embryos (controls) either uninjected or injected with p53 MO alone exhibited identical phenotypes in the tissues examined. (A, B) Migration of FBMNs (arrowheads) into r6 and r7 (A) is mostly eliminated in a tag1 MO-injected embryo (B). Zn5-labeled dorsal commissural neurons (red) at rhombomere boundaries develop in similar numbers in control and morphant embryos. (C, D) While acridine orange (AO) labeling reveals very few dying cells in a control embryo (C), there are many more dying cells (arrowhead) in a tag1 morphant (D). Asterisk marks otic vesicle. (E) In a control embryo, FBMNs migrate in close proximity to the medial longitudinal fascicle (MLF, arrowhead). Arrow indicates the dorsal longitudinal fascicle (DLF) containing the central (afferent) axons of the trigeminal sensory neurons. (F) In a tag1 morphant, the MLF (arrowhead) and DLF (arrow) appear brighter, but develop normally. (G, H) The trigeminal sensory ganglion (arrowhead) in a control embryo (G) is compact (inset shows lateral view), with prominent peripheral axons (arrowhead). In contrast, the trigeminal ganglion in a tag1 morphant (H) is composed of loosely organized cells (arrowheads, and inset showing lateral view), with peripheral axons (arrow) extending broadly over the head. Asterisks indicate the nucleus of the MLF, with brightly-labeled projections in the morphant, compared to the control embryo. (I, J) Expression of krox20 in r3 and r5 is similar between control and tag1 morphant embryos. (K, L) Ventrocaudal migration of tyrosine hydroxylase (TH)-positive locus coeruleus neurons (arrowhead) into r1 is similar between control and tag1 morphant embryos. Scale bar in D (150 μm for C, D); in E (75 μm for A, B, E–H); in J (75 μm for I–L).