Fig. 5. Signaling by P₁ descendants. (A-D) Nomarski photomicrographs showing the division of ABpr in (A) wild-type and (B) mom-2(or42) embryos, and the division of ABpl in (C) wild-type and (D) mom-2(or42) embryos; the asterisk indicates a division into the focal plane. (E) GFP expression of an endoderm-specific transgene after combining isolated EMS and C cells; DAPI staining of the same cells is shown in F. At the time of fixation the EMS daughter distal to C had divided twice, whereas the proximal EMS daughter divided only once. (G) POP-1 expression after the division of combined AB⁴ and MS cells; DAPI staining is shown in H. (I) POP-1 expression after the division of the AB⁴ cells in a devitellinized embryo. Prior to cell division, a graft E cell was placed on one of the AB⁴ cells. Note that AB⁴ daughter proximal to E has low POP-1. J shows superimposed DAPI and PKL-2 images with arrows indicating midbodies.