Figure 5—figure supplement 1—source data 1.

Figure 5—figure supplement 1—source data 1. Two type I BMP receptors display partial redundancy in regulating zswim4-6 expression.

Expression of BMP receptors (A, A’) alk2, (B, B’) alk3/6, and (C, C’) bmprII is broadly detectable in endoderm with a slightly stronger expression on the ‘strong BMP signaling’ side of the directive axis, opposite to chordin (red). (D) qPCR quantification of knockdown (KD) efficiency for BMP receptor shRNAs in relation to shRNA against mOrange (sh_control, 100% expression). Black lines represent the median. (E–I) EGFP signal in late gastrula embryos injected with (E) EGFP mRNA and (F–I) mRNA of dominant-negative BMP receptor constructs in which Ser/Thr-kinase domain was replaced with the EGFP coding sequence. (J) Overview of the expected effect of the dominant negative BMP receptor overexpression and BMP receptor RNAi on BMP signaling. (K–O) zswim4-6 expression is weakly reduced upon overexpression of the dominant negative type I BMP receptors dnAlk2-EGFP and dn_Alk3/6-EGFP and strongly suppressed upon combined overexpression of dn_Alk2-EGFP and dn_Alk3/6-EGFP but remains unchanged upon overexpression of the dominant negative type II BMP receptor dn_BMPRII-EGFP. (P–T) Expression of zswim4-6 is weakly reduced upon Alk2 RNAi, the effect is stronger upon Alk3/6 KD, and zswim4-6 is practically abolished in a combined Alk2+Alk3/6 KD. zswim4-6 expression is unaffected by the BMPRII RNAi. Asterisks mark the oral side. Scale bars 100 µm. The numbers in the bottom-right corner indicate the ratio of embryos displaying the phenotype shown in the image to the total number of embryos treated and stained as indicated in the figure. In (P–T), KD efficiency is shown in the top-right corner of each image.

Figure 5—figure supplement 1—source data 1.