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Fig. 8. Temporal requirement for Irx function during proximal-distal pronephric patterning. Embryos are shown in lateral views and red arrowheads indicate the kidney territory. Embryos were injected in a single blastomere (V2.2) at the 8- to 16-cell stage and lacZ mRNA was used as linear tracer. (A-H) Xenopus embryos injected with HD-GR mRNA. (A-D) Impairment of Irx activity during neurula stages downregulated Sglt1k, Gata3 (A,B) and Nkcc2 (C,D) expression. (E-H) Impairment of Irx activity during tailbud stages did not affect Sglt1k or Gata3 (E,F) but reduced Nkcc2 (G,H) expression. (I-P) Embryos injected with MT-Irx1-GR mRNA. (I-L) Increasing Irx1 function during neurula caused ectopic, patched Sglt1k (I,J) and enlarged Nkcc2 expression domains (K,L). No effect was observed on the duct marker Gata3 (I,J). (M-P) Increasing Irx1 function during tailbud did not affect Sglt1k or Gata3 (M,N) but enlarged Nkcc2 (O,P) expression. (Q-X) Similar results were found in embryos injected with MT-Irx3-GR mRNA. |
