Fig. 6. POP-1 asymmetry in the P₂ daughters. (A) mom-2(or42) mutant embryo at the AB⁴ to AB⁸ division. POP-1 is low in P₃ and high in C, as in wild-type embryos; note that the EMS daughters show little if any POP-1 asymmetry. (C) POP-1 in a devitellinized embryo. Note reversal of POP-1 polarity in the P₂ daughters. (E) POP-1 after the division of combined EMS and P₂ cells. The EMS daughters are entering prophase and hence show low POP-1 levels (see legend to Fig. 2). (G) POP-1 in a devitellinized wild-type embryo after grafting AB² cells from a mom-2(or42) mutant embryo onto P₂. In all experiments the identity of P₃ was confirmed by cell size and by immunostaining for P granules (data not shown). DAPI staining is shown in B,D,F and H.