Table 1. Different mechanisms of inducing DNA hypomethyltion cause distinct phenotypes in early zebrafish embryos.
Embryos were injected with the indicated morpholino (MO) or RNA immediately after fertilziation or were treated with 5-aza before the 16 cell stage. Methylation levels were determined by slot blot analysis with anti-5MeC. Dnmt1 protein was determined by Western blot. Not done (ND).
| Genetic Approach | Change in DNA Methylation |
Embryonic Phenotype |
Dnmt1 Protein |
|---|---|---|---|
| uhrf1 Knockdown (MO) | 60% Residual DNA Methylation |
High Stage Arrest |
Increased |
| dnmt1 Knockdown (MO) | 52% Residual DNA Methylation |
None | Decreased |
| 5-Azacytidine Treatment | 57% Residual DNA Methylation |
Sphere Stage Arrest |
Inhibited |
|
WT-UHRF1 Over- expression (RNA) |
61% Residual DNA Methylation |
Asymmetric Epiboly |
Slightly Increased |
|
UHRF1S661A Over- expression (RNA) |
43% Residual DNA Methylation |
Asymmetric Epiboly |
Increased |
|
WT-dnmt1 Over- expression (RNA) |
32% Residual DNA Methylaton |
Asymmetric Epiboly |
ND |
|
dnmt1C1109S Over- expression (RNA) |
ND | Asymmetric Epiboly |
ND |