Fig. 7. Overexpression of TBX-35 is sufficient to specify pharynx and muscle fates. Images depict terminal embryos that received a 30-minute heat shock at 33°C before the 100-cell stage. (A) Absence of pharynx muscle (ceh-22::GFP) in a skn-1(RNAi) embryo (0.0±0.0 cells, n=36). (B) Small numbers of muscle cells (hlh-1::GFP) made in a skn-1(RNAi); pal-1(RNAi) background (6.7±0.5 cells, n=47). (C) Pharynx muscle cells are made when tbx-35 is overexpressed in a skn-1(RNAi) background. Thirty-two percent of embryos (45/141) had an average of 13.8±1.8 cells per embryo, with 10 embryos containing at least 25 cells as shown here, or an overall average of 4.4±0.8 (n=141). (D) An increase in body muscle cells in a skn-1(RNAi); pal-1(RNAi) background following ectopic activation of tbx-35 (an average of 13.2±1.7 cells, n=87). Fifteen percent of embryos (13/87) had at least 30 muscle cells, similar the embryo shown here. (E) Numbers of pharynx muscle cells (ceh-22::GFP) in a skn-1(RNAi) background. (F) Numbers of body muscle cells (hlh-1::GFP) in a skn-1(RNAi); pal-1(RNAi) background.