Fig. 4. Confocal photomicrographs of PAR-2 and P-granule immunofluorescence in wild type and spn-4 mutant embryos. P granules (green) are segregated to one daughter in the first two cell divisions in fixed wild-type (A,C,E) and spn-4(or80) embryos (B,D,F). In wild-type embryos and spn-4(or80) embryos, P granules are restricted to the posterior cortex during prophase in P1 (A,B). P granules are shifted laterally by anaphase in a spn-4(or80) mutant embryo (D). Note the linear arrays of P granules, particularly in the wild-type embryo (C). Thus, P granules may associate with astral microtubules, although most MTs appear not to have survived fixation in these embryos. During P1 prophase in wild-type and spn-4(or80) embryos, PAR-2 (green) is restricted to the posterior cortex of P1 (G,H). By metaphase, PAR-2 remains posterior in wild type (I). In spn-4(or80) embryos, PAR-2 shifts laterally to form a crescent centered around one pole of the ‘P1’ spindle (J). Microtubules (C,D) are red, DNA is blue.
