| Objective:To study the effect on the embryo development of zebra fish by ?-ray,and further explore the mechanism how the classical Wnt signaling pathway affects the embryonic nerve development of zebra fish after the irradiation of ?-Ray.Methods: Apart zebra fish into A/B groups and irradiate zebra fish embryos growing to 5 hours by bio-irradiation apparatus with different ?-ray dosages(0 Gy,0.25 Gy,0.5 Gy,1.0 Gy,2.0Gy),and then explore the effect of classical Wnt signaling pathway on embryo nerve development of zebra fish after the irradiation of ?-ray?.the observation of the morphological changes in zebra fish embryos caused by 2.0Gy ?-ray under electron microscope;?.the observation of the morphological changes in brain nerve cells of zebra fish embryos growing to 48 hpf,72hpf by silver staining with different ?-ray dosages;?.the statistics of death rate,teratogenic rate and the hacking rate;?.RT-PCR detection of the expression level change of Wnt3 a,DVL2 ?-catenin and mRNA at different developmental timings that 0.5Gy ?-ray did to zebra fish embryos;?.Western blot detection of the expression level change of Wnt3 a,DVL2 ?-catenin and Protein at different developmental timings that 0.5Gy ?-ray did to zebra fish embryos;Results:?.Irradiate zebra fish embryos growing to 5 hours with ?-ray of 0 Gy,0.25 Gy,0.5 Gy,1.0 Gy,and 2.0Gy,then observe the morphology of the embryos growing to 6hpf,12 hpf,24 hpf,36 hpf,48 hpf,72 hpf.Results: the growth of zebra fish embryos irradiated by different doses of ?-ray were influenced by varying degrees,of which the effects of the development of zebra fish embryos in 2.0Gy dose group were especially evident,and there is the development lag of 24 hpf zebra fish embryos under the irradiation of 2.0Gy ?-ray;spinal cord bending of 48hpf's zebra fish embryos and malformation on tails and pericardium cyst of 72hpf's zebra fish embryos;?.After the respective irradiation of 0 Gy,0.25 Gy,0.5 Gy,1.0 Gy,2.0Gy ?-ray on zebra fish embryos developing to 5 hours,then there are the statistics of the hacking rate for48 hpf zebra fish embryos,teratogenic rate of 72 hpf zebra fish embryos,and death rate of 72 hpf zebra fish embryos in group of different irradiation doses.Results: Hacking rate was obviously decreased from the 0.5Gy dose group,and statistically different(P <0.05),compared with the group of 0Gy;The teratogenic rate began to rise from the group of 0.25 Gy,and statistically significant difference(P <0.05),compared with the group of 0Gy;the death rate has a significant increase in the trend from the 0.5Gy dose group,so 0.5Gy dose gamma rays can be considered as certain sensitivity to the development of zebra fish embryos.?.After the respective irradiation of 0 Gy,0.25 Gy,0.5 Gy,1.0 Gy,2.0Gy ?-ray on zebra fish embryos developing to 5 hours,then observe the morphological changes in brain nerve cells of zebra fish embryos growing to 48,72 hpf by silver staining with different ?-ray dosages.Results: The 48 hpf zebra fish embryos showed brain nerve cell arrangement disorder by 1.0Gy dose irradiation,and the gap between the brain nerve cells were enlarged irradiated by 2.0Gy ?-Ray;the cel-shading of brain nerves of 72 hpf zebra fish embryos was different after irradiated by 2.0Gy ?-ray.?.Irradiate zebra fish embryos growing to 5 hours with ?-ray of 0,0.5Gy,then exam the relative genetic expression change of Wnt pathway of the embryos growing to 6 hpf,12 hpf,24 hpf,36 hpf,48 hpf,72 hpf by semi-quantitative RT-PCR.Results: During the growth the expression of Wnt3 a,?-catenin mRNA showed the trend of increase first and then decrease,and the expression of Dvl2 mRNA decreased gradually,and the expression of Wnt3 a,DVL and ?-catenin mRNA in the late stage of growth of dose group had obvious inhibitory effect.?.Irradiate zebra fish embryos growing to 5 hours with ?-ray of 0,0.5Gy,then exam the relative protein expression change of Wnt pathway of the embryos growing to 6 hpf,12 hpf,24 hpf,36 hpf,48 hpf,72 hpf by Western blot detection.Results:During the growth of zebra fish the expression of Wnt3 a,?-catenin mRNA showed the trend of increase first and then decrease,and it was higher than the expression at the the peak in adolescent growth.and the expression of Dvl2 mRNA decreased gradually,and comparing with irradiation group and the comparison group the expression of Wnt3 a,Dvl2 and ?-catenin protein was inhibited.Conclusion:?.The lower dose of ?-Ray(0.25Gy~2.0Gy)can toxicity of zebrafish neural development,possibly through classic Wnt signaling pathways that control neural development of zebrafish embryos.?.Early development(5 HPF)of zebrafish embryos be used as low doses of radiation 0.5 Gy sensitive biological early warning model of animals,Wnt3a?Dvl2??-catenin gene and protein expression can be used as a sensitive biomarker. |
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