Figure 4. Hemicentin-1-Deficient Embryos Arrest Prior to Implantation with Multiple Nuclei.
(A–D) Images of age-matched wild-type (A and B) and hemicentin-1-deficient (C and D) embryos from matings of wild-type and hemicentin-1 heterozygous parents. DIC images are shown with corresponding nuclear staining with YOYO-1 (green) and anti-myosin IIB (red). Scale bars represent 20 μm.
(A and B) Wild-type embryos progress to the two-cell stage with mononucleate cells (arrowheads) and external polar bodies (arrow).
(C and D) In contrast, hemicentin-deficient embryos arrest prior to the four-cell stage. Arrested embryos contain multinucleate cells (arrowheads; Figure S3), multiple invaginations in the plasma membranes, and internal polar bodies (arrow).
(E–G) Time-lapse photography of wild-type and hemicentin-deficient embryos in Movie S1 and Movie S2 during the first 3 days of development. Wild-type embryos have external polar bodies and develop to the four-cell stage (E; Movie S1). In contrast, hemicentin-1-deficient embryos develop membrane invaginations (arrows) and internal polar bodies (arrowhead), but membrane invaginations do not proceed to completion and often retract (F and G; Movie S2).