Fig. 4. Polarity markers are disrupted in pam-1. (A-E) Laser scanning confocal images of PAR-2 and PAR-3 in fixed embryos using indirect immunofluorescence. DNA was stained with TOTO. (A,A',D,D') Before and during the first cell division in wild type, PAR-2 localized to the posterior cortex of the embryo and PAR-3 to the anterior cortex. (B,B') In many one-cell pam-1 embryos, PAR-2 did not localize to the cortex, but was found instead on cytoplasmic puncta around the pronuclei. (C,C') When PAR-2 did localize to the cortex, it was often at a lateral position. (E,E') In roughly half of pam-1 embryos, PAR-3 localized around the entire periphery. (F-G') PGL-1 antibody staining of the P granules in fixed embryos using indirect immunofluorescence. (H-I') Fluorescent images of PIE-1::GFP taken in living embryos at the one- and two-cell stage. (F,F') During the one-cell stage in wild type, the germline P granules localized to the posterior pole and were segregated into the posterior daughter cell P₁. (H,H') Similarly, the transcription factor PIE-1 localized to the posterior and was found in the cytoplasm and nucleus of the P₁ cell. (G,G') In pam-1 embryos, the P granules were frequently mislocalized during the first division and often found in both cells at the two-cell stage. (I,I') PIE-1 failed to become properly partitioned during the first division, and was absent from both daughter cells in embryos that divided symmetrically. Scale bar: 10 µm.