Figure 7.

Testing a unique prediction of our model: tumor incidence is affected by long-range signaling across the left-right axis but not across the dorso-ventral axis. (A) (i) Embryos were injected with H7 and KRAS^G12D, separately and randomly, in the dorsal and ventral blastomeres. (ii) Embryos were also injected with H7 and KRAS^G12D in the left and right blastomeres, or vise versa. Control embryos injected with KRAS^G12D only displayed a 35% tumor incidence. (B) Compared to controls, embryos injected with KRAS^G12D and H7 across the dorsoventral axis did not show a change in tumor incidence (32.4%). Whereas perturbation of GJC communication across the left-right axis significantly lowered tumor incidence down to 20.5% (^*P < 0.05, X² test).