Figure 1.

Epistasis study in the eye and embryo. (A) Schematic diagram of the Wg pathway and the planar cell polarity pathway. Arrows and bars show positive and negative actions, respectively. P represents the phosphorylated state of Dsh. See text for details. (B–J) Nkd can suppress Wg and Dsh misexpression eye phenotypes, but not the Arm^S10misexpression eye phenotype. Ventral is to the left and anterior up. (B) The wild-type adult eye consists of an array of ommatidia and interommatidial bristles. (C,E) The sev-wg or UAS-dsh eyes lack bristles and/or ommatidia. (G) The UAS-arm^S10 eye has disrupted ommatidia and loss of bristles (average number of bristles/eye = 11.6; n = 8). (D,F) Co-misexpression of UAS-nkd dramatically suppressed the sev-wg (n = 8) and the UAS-dsh (n = 8) eye phenotypes. (H) Co-misexpression of UAS-nkd did not suppress the UAS-arm^S10 phenotype (average number of bristles/eye = 5.4; n = 8). UAS-GPI-Dfz2 suppresses the sev-wg loss of bristle phenotype (I) but does not suppress the UAS-dsh phenotype (J). (K,L) Injection of Xenopus GSK3β mRNA into nkd mutant embryos can restore denticles to the nkd embryos. Anterior is up. (K) nkd mutant embryos lack ventral denticle belts. (L) Injection of GSK3β into nkd^7H16 embryos restored ventral denticles (brackets). nkd^7H16 mutant embryos were identified by a Ubx mutation resulting in the transformation of the first abdominal segment A1 to the third thoracic segment T3 (arrow).