Figure 5. Model of VPC Orientation (A) Illustration of the genetic interactions contributing to the orientation of P7.p and the nuclear localization of POP-1, WRM-1, LIT-1, SYS-1, and BAR-1 in ground and refined polarity. We have examined WRM-1 and LIT-1 localization in refined polarity, but WRM-1 and LIT-1 localization in ground polarity is inferred from POP-1 localization, which was previously described (Deshpande et al., 2005). Localization of SYS-1 and BAR-1 in ground and refined polarity was described here. (B-D) Schematics of default, ground, and refined polarity. In the absence of Wnts, the orientation of P5.p and P7.p (white circles) is random (represented by a question mark) (B).
egl-20/Wnt is expressed in the tail (green circles) and establishes ground polarity in which both P5.p and P7.p (blue circles) face posteriorly (arrows) (C). Wnts
mom-2 and
lin-44 are expressed in the AC (big green circle) and instruct P5.p and P7.p (red circles) to face the center (arrows) (D).