On X-ray Sensitivity in Xenopus Embryogenesis

We examined the effects of X-ray irradiation on Xenopus laevis , focusing on pre- and post-fertilization exposure. We applied X-ray doses of 10, 50, 100, 250, and 500 Gy. 50% of 360 eggs irradiated at 250 Gy failed to fertilize, while fertilized eggs developed normally until the blastula stage. Doses of 10-50 Gy caused developmental anomalies, with significantly lower mortality than doses of 100-500 Gy. Post-fertilization irradiation of 50-100 Gy led to higher lethality than exposure of 10 Gy, although with similar kinds of developmental anomalies to pre-fertilization irradiation. The study highlights how the timing and intensity of exposure critically affect embryo viability, especially during the sensitive stages of fertilization and gastrulation. We establish the necessary and sufficient dosage to further investigate the molecular mechanisms of X-ray damage to both DNA and proteins.