Practice question

EMS fate specification integrates Wnt signaling from neighbor P2 historically termed Wnt/MAPK or Wnt/beta-catenin asymmetry pathway. MOM-2 Wnt produced by P2 signals via MOM-5 Frizzled, MOM-4 TAK1 MAPKKK, WRM-1 beta-catenin, LIT-1 Nemo-like kinase to EMS, activating MAPK-like cascade depleting nuclear POP-1 TCF from posterior daughter E via phosphorylation-triggered export. Low POP-1 converts from repressor to activator enabling END-1,3 expression and gut differentiation. Notch pathway distinguishes AB fate, but EMS specification relies primarily on Wnt asymmetry. Genetic removal of mom genes converts E to MS.