Figure 1

Physical and molecular anterior-posterior polarity requires emb-8 function. Images of emb-8(+) (A-D) and emb-8(hc69) mutant embryos (E-K). Representative DIC images of two cell embryos (A, E) and immunolocalization of PAR-3 (B, F, and I), PAR-2 (C, G, and J), and germline granules (D, H, and K) in one-cell embryos. All embryos are oriented with anterior to the left and each image represents a different embryo. All fluorescent images and data represent analysis of one-cell embryos between pronuclear meeting through anaphase of the first cell cycle when PAR-3, PAR-2, and germline granules are normally asymmetrically distributed. All Wild-type embryos (A) divide asymmetrically and restrict (B) PAR-3 and (C) PAR-2 to the anterior and posterior cortices, respectively. (D) Germline granules are segregated to the posterior cytoplasm. (E) Half of emb-8(hc69) mutant embryos divide symmetrically. Some emb-8 mutant embryos show (F) uniform cortical PAR-3 localization; 5/13; (G) reduced PAR-2 domains at the posterior; 5/15; and (H) centrally dispersed germline granules; 6/22. Other emb-8 mutant embryos show (I) reduced, lateral localization of cortical PAR-3; 5/13 ; (J) mislocalization of PAR-2 to the posterior-lateral cortex; 6/15; (K) and mistargeted segregation of germline granules to posterior-lateral corners; 5/22.