Fig. 2. Reciprocal nuclear asymmetry of GFP::SYS-1 and POP-1 between A-P sisters. Immunofluorescence micrographs of teEx321(P_med-1gfp::sys-1) C. elegans embryos. (A-D) Embryos at 1MS/1E stage stained with (A) anti-GFP antibody, (B) anti-POP-1 mABRL2 and (D) DAPI to visualize nuclei. (C) Merged image. (E-L) Anti-GFP (left) and corresponding DAPI staining (right) at 2E stage (E-H), 4E stage (I,J) and 8E stage (K,L) of embryogenesis. White lines connect nuclei of sister cells born from A-P divisions; black lines connect nuclei born from left-right divisions. The cortical GFP signal often appeared asymmetric, being observed at the anterior cortex of anterior cells (white arrowheads) but not at the posterior cortex of posterior sisters (open arrowheads). Scale bar: 10 µm.