Fig. 2. The phenotypes of xKaiso-depleted embryos. (A) Embryos injected at two-cell stage with 10 ng of a control morpholino (CMO) show normal neurulation (stage 15). (B) Injection of 5 ng of the xKaiso morpholino (KMO) leads to a failure of blastopore closure and developmental arrest of neurulation at stage 15. Arrows indicate the appearance of white apoptotic cells from the borders of the blastopore. (C) Apoptotic cells (arrowed) cover almost the entire surface of embryos at stage 21 and cell shedding is present. (D) Injection of low dose (0.5 ng) of KMO causes defects of neurulation and delay of blastopore closure. Apoptotic cells are arrowed. (E) The range of phenotypes produced at low dose (0.5 ng) of KMO: 44% of embryos look normal by stage 38 (upper embryo), 29% exhibit failure to develop normal dorsal structures (spina bifida, lower embryo). Other phenotypes are intermediate. (F) Embryos injected with 10 ng of xDnmt1 morpholino (DMO) show apoptotic phenotype virtually identical to that of 5 ng KMO. (G) Western blot using anti-xKaiso antibody and whole embryonic extracts derived from wild type (WT) and 5 ng KMO-injected embryos (KMO). Stages of development are indicated above the lanes. The kaiso-specific band in KMO-injected embryos disappears by stage 10.