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Figure 6
(A) Impact of acvr1 loss-of-function and acvr2b-a overexpression on Squint- and Cyclops-Dendra2 clearance rate constants determined using FDAP measurements. For acvr1 loss-of-function, 0.4 ng acvr1b-b MO-1 were injected into acvr1b-a-/- mutant embryos. For overexpression, 100 pg acvr2b-a mRNA were injected into wild-type embryos. Mean extracellular clearance rate constants are displayed in red, and individual measurements are shown as black dots. Error bars represent 95% confidence intervals. See Figure 6—figure supplement 1A for representative fits. (B) Influence of receptor levels on Squint- and Cyclops-GFP diffusivities determined using FRAP measurements. For overexpression, either 50 pg oep mRNA or 100 pg acvr2b-a mRNA were injected into wild-type embryos at the one-cell stage. acvr1b-a mutants and 0.4 ng acvr1b-b transcriptional start site-targeting morpholino (MO-1) were used for receptor loss-of-function conditions. The mean diffusion coefficients are displayed in red, and individual measurements are shown as black dots. Error bars represent 95% confidence intervals. See Figure 6—figure supplement 1B for representative fits. Scale bars represents 100 µm. (C) Margin-to-animal pole transplantations show that Nodals at endogenous expression levels can signal to distant cells. Top panel: Experimental setup of the margin-to-animal pole transplantations, in which wild-type embryos or MZsqt-/-;cyc-/- embryos that lack Nodal relay were used as hosts. Bottom panel: Immunofluorescent stainings show that pSmad2/3-positive nuclei (green) are detected outside of the transplanted clones (magenta) in both wild-type (top row) and MZsqt-/-;cyc-/- (bottom row) hosts. (D) Margin-to-margin transplants show that Nodals at endogenous expression levels can signal to distant cells at the embryonic margin. Top panel: Experimental setup. Bottom panel: Representative maximum intensity projections of immunofluorescent stainings. Transplantations into wild-type embryos (top row) and MZsqt-/-;cyc-/- embryos (bottom row) are shown. Scale bars represent 200 µm. Animal pole views are shown in (A–D). See the Figure 6—source data 1 file for source data and sample size.
Influence of Nodal receptors on Nodal stability, diffusivity and autoregulatory signal propagation.