Figure 6.

Gamma-ray irradiation on the embryos at late embryogenesis period resulted in the incomplete development of brain. Medaka embryos at 3 dpf were irradiated with 10 Gy gamma-rays and maximum width of OT were measured at 2 and 4 days after the irradiation (A). Each independent data was shown with black circled marker in A. At 2 days after the irradiation, the maximum width of OT of the irradiated embryos (C) were smaller than the non-irradiated sham controls (B) with a statistical significance. At 4 days after the irradiation, OT of the irradiated embryos (E) were still smaller than the non-irradiated sham controls (D) with a statistical significance. Retina of the irradiated embryos were also smaller than the sham controls at 2 days after the irradiation (arrowheads in B,C). All of the irradiated embryos hatched normally. A p * value < 0.05 was considered statistically significant and p ** < 0.01 was considered highly statistically significant. Scale bar = 50 μm.