Fig. 7

Dnmt1 overexpression phenocopies the asymmetric epiboly phenotype of UHRF1 and UHRF1^S661A overexpressing embryos. (A) Developmental progression of uninjected and WT-dnmt1 overexpressing embryos at indicated stages. At High Stage (~3.3 hpf) all embryos appear normal, at 50% epiboly (~5.25 hpf) and Shield stage (6.0 hpf) arrows indicate asymmetric epiboly and lack of dorsal organizer. At Bud stage (10.0 hpf) arrow points to the front of the migrating cells indicating delayed completion of epiboly. At Prim-5 stage (24.0 hpf) arrows indicate severe defects in head and tail with lack of head and tail extension. (B) Embryos were scored at 6 hpf for asymmetric epiboly and delay following injection of 1, 10, 12.5, 25, 50 or 100 pg of WT-dnmt1 mRNA (sense) or 25, 50, or 100 antisense dnmt1 RNA as a negative control. The number of clutches, total number of embryos scored and percent of asymmetric epiboly are indicated. (C) Overexpression of catalytically inactive dnmt1^C1109S (MT-dnmt1) causes asymmetric epiboly. Asterisk indicates statistical significance (p<0.05) using Fisher′s exact test. The number of embryos and biological replicates are indicated. n.s.=not significant.