FIGURE 3.
Stage-dependent effects of RA or RA antagonist on the left-sided Nodal signal in the LPM. 84.1 and 86.2% of DMSO-treated embryos showed left-sided spaw (A) and lefty2 (G), respectively. In contrast, 73.2 and 83.1% of embryos treated with BMS453 from 32-cell to 2So exhibited bilateral expression of spaw (p < 2.0 × 10−5; n = 71) (B) and lefty2 (p < 3.0 × 10−6; n = 65) (H), respectively. 83.6 and 79.8% of embryos treated with BMS453 from 2So to 22So displayed left-sided spaw (p > 0.93; n = 73) (C) and lefty2 (p > 0.09; n = 79) (I), respectively. 65.0 and 83.3% of embryos treated with RA at the shield stage for 1 h and 20 min exhibited bilateral expression of spaw (D) and lefty2 (J), respectively. 72.8 and 89.4% of embryos treated with RA at the 4-somite stage for 1 h and 20 min showed left-sided spaw (E) and lefty2 (K), respectively. F, percentage of embryos showed different sideness of spaw expression. L, percentage of embryos showed different sideness of lefty2 expression. No tail was applied to label the midline (G–K). Embryos were subjected to in situ hybridization at 22So and observed. M and N, expression of charon around KV at 10So in embryos with DMSO (M) or BMS453 (N) treatments before 2So. p values were calculated against control embryos treated with DMSO.