Fig. 5. The gpa-16(it143) mutation reduces centrosomal association of the Gß protein GPB-1 in early cleavages at 25°C. Embryos were stained with DAPI (blue), rabbit anti-GPB-1 visualized using an FITC-conjugated secondary antibody (green), and mouse anti-tubulin visualized with a TRITC-labeled secondary antibody (not visible). Mitotic cells were identified by their chromosomal (DAPI) and spindle (anti-tubulin) morphologies (not shown), recorded prior to examination of anti-GPB-1 staining. (A) Wild-type embryo showing cortical (white arrows) and centrosomal (red arrowheads) GPB-1 staining in a prophase nucleus. (B) A gpa-16 embryo at 25°C shows cortical but not centrosomal staining; red arrowheads indicate a metaphase and a prophase nucleus. (C) gpa-16(it143) embryo at 16°C showing both cortical and centrosomal staining. See text for quantitative data.