Figure 3. Regulation of ecrg4b expression by Yap1 and Wwtr1.

(A,B) ecrg4b is expressed in the presumptive epidermis of sibling embryos (A) but is not expressed in yap1;wwtr1 double mutant embryos (B). (C–F) Transgenic embryos obtained from an outcross of hemizygous HS:DN-yap or HS:CA-yap adults were heat shocked at the 4-somite stage and then raised to 18 somites. The genotype of the embryos was determined by PCR after the in situ hybridization to be either transgenic or non-transgenic control. Expression of DN-yap decreased ecrg4b expression relative to non-transgenic controls (C,D, n = 6 for each) whereas CA-yap enhanced ecrg4b expression (E,F, n = 4 for each). (G,H) Embryos analyzed using FISH probe to ecrg4b demonstrates that CA-yap increases expression of ecrg4b only in the epidermis (n = 4 for each). All embryos are at the 18-somite stage.

Figure 3—figure supplement 1. Regulation of wu:fc23c0 by Yap1 and Wwtr1.

(A,B) wu:fc23c0 is strongly expressed throughout the notochord of sibling embryos (A) but not expressed in the posterior notochord of yap1;wwtr1 double mutant embryos. (C–E) Transgenic embryos obtained from an outcross of hemizygous HS:DN-yap or HS:CA-yap adults were heat shocked at the 4-somite stage and then grown to 18 somites. The genotype of the embryos was determined by PCR after the in situ hybridization to be either transgenic or non-transgenic control. Expression of DN-yap decreased posterior notochord wu:fc23c0 expression (D, n = 10) whereas CA-yap did not appear to alter wu:fc23c0 expression (E, n = 8) relative to control non-transgenic embryos (C).

Figure 3—figure supplement 2. Yap1 and Wwtr1 do not regulate arhgap12 and arhgap27 expression.

(A,B) arhgap12a and (C,D) arhgap27 are expressed in the presumptive epidermis at the same level in sibling and yap1;wwtr1 double mutant embryos. The yolk is blue from the prolonged development times necessary to visualize these weakly expressed transcripts.