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Figure 2. Inducible activation of Lhx1, defines a temporal window of kidney field expansion.Embryos were injected (1xV2) with 200 pg of LL-VP16-GR mRNA at the 8-cell stage. (A–L) In situ hybridization for pax8 of embryos at stage 31, followed by MZ15 whole-mount immunostaining. (A, C, E, G, I, K) Uninjected embryos. (B, D, F, H, J, L) Injected embryos. Activation of LL-VP16-GR was controlled by addition of dexamethasone (Dex) at specified stages. Dex was added to uninjected and injected embryos at: (A, B) stage 10; (C, D) stage 12.5; (E, F) stage 15; (G, H) stage 18; (I, J) stage 21; (K, L) stage 24. (M) Bar graph with the percentage of injected embryos that showed expansion after Dex treatment at different stages. Expansion of pax8 expression was observed in 53% of the embryos for stage 10 (n = 36), 56% for stage 12.5 (n = 32), 84% for stage 15 (n = 32), 79% for stage 18 (n = 34), 40% for stage 21 (n = 45) and 24% for stage 24 (n = 21). |
