The Establishment And Mechanism Research Of C.elegans Dose Effect Model In Neutron Irradiation Biology

Neutron irradiation is being widely applied in the fields of agriculture,national defense,radiotherapy,and the nuclear industry.Multiple studies have shown that neutron irradiation,as a high Linear Energy Transfer(LET),can trigger severe biological effects.In recent years,low dose hyper-radiosensitivity(HRS)response in cells induced by low LET irradiation has been discovered by a large number of studies.With the wide application of neutron irradiation,it is necessary to study whether low dose neutron irradiation can trigger the HRS response.This study irradiated the in vivo model organism Caenorhabditis elegans(C.elegans)with the High-Intensity D-T fusion Neutron Generator(HINEG)to detect and analyze the survival fraction and reproductive function of C.elegans,and to investigate the mechanism of the mutagenesis induced by low dose neutron irradiation.Based on the researches of the current Induced Repair Model of the HRS response induced by low LET irradiation and the damage-repair model for mutagenic effects of heavy ions~7Li irradiation,the target theory model and the mutagenesis theory model induced by low dose neutron irradiation of C.elegans were established.And the survival fraction of C.elegans on the 12th day after low dose neutron irradiation was analyzed,which showed a low dose hyper-radiosensitivity response.By comparing the experimental results with the theoretical model,it was speculated that the DNA damage induced by low dose neutron irradiation and the immune repair effect played an important role in the generation of the hyper-radiosensitivity response.To explore the effects of low dose neutron irradiation induced DNA damage on the reproductive function of C.elegans,the results of germ cell apoptosis and brood size of worms were analyzed and compared with?-ray irradiation.It is shown that neutron irradiation could induce the germ cell apoptosis of worms increase linearly with a threshold trend and could induce genetic damage in the progeny of C.elegans.Real-time quantitative PCR results showed that the DNA damage pathway was involved in the process of germ cell apoptosis induced by low dose neutron/?-ray irradiation,and the relative biological effectiveness(RBE)value of neutron irradiation was about 1.21.In summary,the low dose neutron irradiation induced a low dose hyper-radiosensitivity response of the survival fraction of C.elegans on the 12th day.Based on target model and the damage-repair model for mutagenic effects,a theoretical hypersensitivity model of survival fraction was established,and it was proposed that DNA damage repair and innate immune system of C.elegans played important roles in neutron-induced hypersensitivity.Using low dose neutron/?-ray irradiation as irradiation source,which induced the germ cell apoptosis of C.elegans increased linearly with a threshold trend,and found that the DNA damage pathway mediated the radiation-induced apoptosis signal transduction in worms.These results provided a reference for the health risk assessment of neutron irradiation damage,the establishment of radiation safety standards for professionals and the general public,the clinical neutron therapy,and the neutron radiation protection...