Cell adhesion and cytokinesis are affected in MZikk2 −/− embryos. (A–D) Early cell adhesion and cytokinesis defects in MZikk2 −/− embryos (obtained from homozygotic parents, arrow) were followed by the ‘cellular island’ phenotype (arrow) at sphere stage. (E,F) (H,E) stained sections showing abnormal nuclear clumps in the EVL (arrow) and enlarged YSL (arrowhead) of MZikk2 −/− embryos. (G-I) krt8 WISH reveals multinuclear cells in MZikk2 −/− embryos. (I,I′) Blowup of boxed areas in (H,H′), respectively. (J–L) Whole-mount immunostaining using Phalloidin and DAPI shows cell boundaries (K,K′) and nuclei (L,L′) in MZikk2 −/− embryos (animal pole view, sphere stage). (M,N) Cell division furrows stained by E-cadherin, 8-cell stage. (O) Quantification of embryos with mild and severe division furrow defects based on E-cadherin staining. (P) A number of embryos in ikk2 −/− crosses as compared to wild-type; p < 0.001, Student’s t test. (Q) Ikk2-dependent phosphorylation of Aurora-A in extracts of ikk2 −/− and controls. Actin and Coomassie blue, loading control. All data are expressed as mean ± SEM; Scale bar in all panels: 100 μm.
|