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Wnt Signal Transduction in the Early Embryo Figure 1: Wnt expression in whole HB a mounts and cryosections of head E 8.5 b ba1 from E8.5 to E11.5 ba1 ba1: first branchial arch, ot: CNC a b LT a FB b otocyst, FB: Forebrain, LT: Lamina a Terminalis, HB: Hindbrain, MB/HB: a E9.5 ba1 Midbrain-Hindbrain Junction, OE: b ot ba1 b Oral Epithelium, CNC: Cranial HB Neural Crest, TG: Trigeminal a HB b a b Ganglion FB a E 10.5 ab LT b LT ba1 eye ba1 c c MB/HB TG a b c a b c FB LT E 11.5 aa LT OE eye bb MB/HB ot eye c c a b c a b c Wnt Signal Transduction in Later Stages of the Embryo a CC OE OE ba E 12.5 cb CF CF dc LT d HT ee MB MO MO ot OP OP a a b b cc d d e e CC OL a a eye ns E 13.5 b b CE c c CC T d d MB MB T e e MB/HB MB/HB a b cc d ee CC a b d a CC OL ns a eye E 14.5 bb R cc MB CE dd e MB b P/MB SE SE d nt a a b b c c d e e a a b b HF E 16.5 TS a MO R b PC HF b a Figure 4: TCF-LEF/LacZ expression in the Wnt signaling reporter in whole mounts and cryosections of head from E12.5 to E16.5; ba1: first branchial arch, ot: otocyst, ns: nasal septum, nt: neural tube, hf: hair follicle; see Table 1 for expanded key Key Structures that Process Wnt Signaling in Later Stages E12.5 Future Cerebral Cortex (CC), Lamina Terminalis (LT), Midbrain (MB), Medulla Oblongata (MO), Choroidal Fissure (CF), Hypothalamus (HT), Olfactory Epithelium (OE), Otic Placode (OP) E13.5 Lamina Terminalis (LT), Midbrain-Hindbrain Junction (MB/HB), Midbrain (MB), Future Cerebral Cortex (CC), Corneal Epithelium (CE), Future Olfactory Lobe (OL), Tongue (T) E14.5 Future Cerebral Cortex (CC), Midbrain (MB), Surface Ectoderm (SE), Pons-Midbrain Junction (P/MB), Future Olfactory Lobe (OL), Corneal Epithelium (CE), Retina (R) E16.5 Hair Follicle (HF), Medulla Oblongata (MO), Primitive Cerebellum (PC), Thalamus (TS), Retina (R) Table 1: Key structures in later stages of development that process Wnt signal reporter. Figure 3: Wnt signal reporter expression in the dermis at E13.5, E14.5 and in the hair follicles at E16.5. Cranial Neural Crest Cells Process Wnt Signal d ba1 Beta-gal Beta-gal brain AP2α AP2α ba1 E 8.5 c ba1 ba1 c d Figure 4: Double immunostaining in the head for AP-2 alpha (red), a neural crest 3: marker, and beta-gal (green). Dermal Progenitors Process Wnt Signal Dermo1 Dermo1 Dermo1 TCF-Lef-LacZ E 9.5 ba1 ba1 ba1 A ba1 ba1 E 10.5 ba1 B E 11.5 C Figure 5: Figure 4: Whole mounts and cryosections of head probed with Dermo1, a dermal progenitor marker. Dermal progenitors prior to E11.5 process Wnt signaling in the branchial arches (ba). Sections A-C show Wnt signal in TCF-LEF cryosections of the head. Figure 6: In the conditional absence of beta-catenin in the En1 lineage, loss of TCF/LEF-LacZ signal is seen in the mid-hindbrain region, branchial arches (ba1), and frontonasal mass (fnm). TCF/LEF-LacZ signal is preserved in non-En1 lineages.
"Wnt Signal Transduction in the Early Embryo"