| |
Fig. 6. Early notch-ICD and wnt4 overexpression promotes medial pronephrogenesis at the expense of lateral pronephric cell fates. (A-C) X. laevis embryos injected with notch-ICD mRNA, cultured to stage 32, and in situ hybridised for nephrin expression, were paraplast sectioned (A). notch-ICD overexpression causes the domain of nephrin expression to extend laterally. Paraplast wax sectioning of stage 41 embryos injected with notch-ICD mRNA highlights the severity of this phenotype (B,C). Normal pronephric layout in section can be observed on the uninjected side of B. On the injected side of this embryo, a mass of non-distinct cells can be observed proximally (B), and in the distal region ectopic nephrostomal tubules and podocytes can be detected (C). Regions of interest are outlined (dashed lines). Asterisk denotes injected side. gl, glomus; cc, coelomic cavity; pt, proximal tubules; end, endoderm; nc, notochord; som, somites; nt, neural tube; ns, nephrostomes; dt, distal tubules. |
