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Figure 1. Expression and regulation of Xenopus Numb and NumbL. (A) Schematic representation of the mouse Numb proteins. The EH motifs are in orange. (B) RT-PCR analysis using X. tropicalis cDNA. Primer pairs used spanning the putative insert regions of the isoforms are indicated on the right side. Arrows indicate the expected PCR products. (C-N) Whole mount in situ expression analysis of X. laevis embryos using a X. tropicalis Numb or X. laevis NumbL antisense RNA probe. Stage 11 embryos shown in C and I are a blastopore view with the dorsal side up. Stage 15/16 embryos are shown in an anterior view (D and J) a dorsal view anterior up (E and K), as well as in transversal sections (F and L). Stage 30 embryos are shown in a lateral view (G and M) and as a transversal section at the level of the hindbrain (H and N). The plane of the transversal sections of E, G, K and M are indicated with a white dotted line. (O) RT-PCR analysis of X. laevis animal caps injected with 20 pg Neurog1-3 mRNA. Explants were cultured until control siblings reached stage 15. H2O represents a negative control where no RNA was added to the RT reaction. (P-S) Whole-mount in situ hybridization of stage 14 embryos injected with Neurog2 (20 pg) or NICD (50 pg) mRNA together with β-Gal (75 pg) mRNA (light blue staining). The injected side is on the right and embryos are shown as a dorsal view. The red asterisk in R and S marks the intermediate stripe that is inhibited on the NICD-injected side. bp, blastoporous; nc, notochord; m, medial stripe; i, intermediate stripe; l, lateral stripe; ba, branchial arches; ol, olfactory placode; ov, otic vesicle; pn, pronephros; pp, panplacodal primordium; vz, ventricular zone; svz, subventricular zone. |
