Table 2.
Antagonistic interaction between Sfrp variants and Wnt8/Wnt5
| Wnt8 (50 ng/μl) | Wnt5 (50 ng/μl) | |||
|---|---|---|---|---|
| Co-injected mRNA | n | Percentage of embryos showing a reduced forebrain |
n | Percentage of embryos showing a reduced forebrain |
| None (Wnt8/Wnt5 alone) | 107 | 88 | 81 | 86 |
| Sfrp1 (200 ng/μl) | 81 | 0 (30) | 78 | 0 (90) |
| Sfrp1CRD (100 ng/μl) | 68 | 96 | 72 | 83 |
| Sfrp1NTR (120 ng/μl) | 110 | 20 (14) | 90 | 7 (60) |
| Sfrp3 (200 ng/μl) | 96 | 87 | 98 | 69 |
| Sfrp3CRD (120 ng/μl) | 117 | 92 | 81 | 93 |
| Sfrp3NTR (100 ng/μl) | 94 | 60 | 89 | 72 |
Percentage of embryos showing a size reduction of the forebrain/optic vesicles upon injection of equimolecular amounts of mRNAs encoding Wnt8 or Wnt5 together with different variants of Sfrp1 and Sfrp3 mRNAs. Representative embryos are shown in Figure 2 and Additional file 2. Wnt8-induced forebrain reduction is much more severe (optic vesicles are completely absent), than that observed upon wnt5 over-expression, where the optic vesicles are, in general, significantly reduced in size but still visible. In the case of Wnt and Sfrp1 and Sfrp1NTR co-injections, the number shown in brackets represents the frequency of appearance of the anteriorised phenotype (enlarged forebrain tissue), which is reduced compared to the over-expression of the given Sfrp construct alone (Table 1).