Study On Radiation Resistance And Mitomycin C Resistance Of DR-pprM/pprI Transgenic Drosophila

Objective: Deinococcus radiodurans(DR)can withstand extremely high doses of ionizing radiation,mitomycin C(MMC),hydrogen peroxide and other extreme environments,and the pprM/pprI gene plays a great role in it.In this experiment,after the pprM/pprI gene of DR strain was transferred into Drosophila,through gamma irradiation and MMC treatment,the physiological indexes and oxidative stress levels of the transgenic Drosophila were observed to verify pprM/pprI effects of genes on radiation and MMC resistance in Drosophila melanogaster,to study the function and mechanism of DR-pprM/pprI gene in heterologous organisms.Provide a basis for further human radiation protection research and clinical use of MMC.Methods:1.PCR technology was used to identify DR-pprM / pprI transgenic fruit flies.Then,the DR-pprM / pprI transgenic fruit flies and the control fruit flies yw25C6 and yw68A4 were treated with different doses of 137Cs-? rays to determine their reproductive,survival and exercise ability,and observe whether the fruit flies in each group were deformed after irradiation,and statistically rate.2.After feeding the pprM/pprI transgenic drosophila and its control drosophila yw25C6 and yw68A4 with different concentrations of MMC(0,40,80 ?g/mL)in the medium,the reproductive,survival and motor ability indexes were determined to explore whether the pprM and pprI genes cod improve the ability of the drosophila to resist mitomycin C.The total protein of each group was extracted after 14 days with different concentrations of MMC(0,40,80 ?g/mL),and the catalase(CAT)activity,total superoxide dismutase(SOD)activity,malondialdehyde(MDA)content and reduced glutathione(GSH)content of each group were detected.Oxidative damage of drosophila adts before and after MMC treatment was evaluated.Results:1.pprI and pprM genes were identified by PCR in drosophila without loss.In the early stage,our laboratory has proved that pprI and pprM genes can be expressed stably in drosophila,which can be used in the following experiments.With the increase of radiation dose,the survival rate of drosophila decreased.When the radiation dose reached 2000 Gy,the survival rate of transgenic drosophila significantly decreased less than that of the control group,and the difference was statistically significant.When the radiation dose reached 200 Gy,the motor ability of drosophila in the experimental group decreased less than that in the control group,and the difference was statistically significant.When the radiation dose was 0 Gy,the reproductive ability of the experimental group was basically the same as that of the control group;when the radiation dose was 50 Gy,the reproductive ability of pprM transgenic drosophila was significantly higher than that of the control group;when the radiation dose was 100 Gy,the reproductive ability of pprM transgenic drosophila and pprM transgenic drosophila were both higher than th at of the control group,showing a statistical difference(P < 0.05).When the radiation dose was 210 Gy,the deformity rate of pprM/pprI transgenic drosophila was significantly lower than that of control drosophila(P < 0.05).Under the same conditions of irradiation treatment,the pprM/pprI transgenic drosophila set of existence,movement and ability to reproduce were higher than control group in fruit flies(P < 0.05),and deformity rate is lower than control group(P < 0.05),and the pprM transgenic drosophila and the pprI transgenic drosophila under the same irradiation dose each index had no obvious difference,explain pprI and pprM gene can improve the radiation resistance of fruit flies,but pprI compared with pprM gene in fruit flies there was no significant difference between the increase of radiation resistance.2.Through the observation of the growth status,climbing ability and spawning capacity of the transgenic flies and their control flies treated with different doses of MMC,it was found that when mitomycin reached 80 ?g/mL,the pprM/pprI transgenic flies reduced less in survival,climbing and fertility than the control group,with statistical significance(P < 0.05).This indicated that pprM and pprI genes cod reduce the damage caused by mitomycin to drosophila,and pprM and pprI genes cod enhance the MMC resistance of drosophila.Moreover,there was not any difference between pprI and pprM in the improvement of MMC resistance in Drosophila.pprI and pprM transgenes and their control flies were treated with 0,40 and 80 ?g/mL MMC,flies was detected in the ROS,SOD,MDA,GSH and CAT values,the rests showed that transgenic flies compared with the control group with concentration,quotiety of superoxide dismutase(SOD),glutathione and activities of catalase content raising,malondialdehyde content reduce,suggests that pprI,pprM gene in fruit flies may by raising its antioxidant enzyme activity of Drosophila,reduce the MMC physiological and biochemical damage to fruit flies.Conclusion:1.Targeting of pprM and pprI genes can significantly improve the radiation resistance of Drosophila.Under the irradiation treatment under the same conditions,the survival,movement and reproductive capacity of the DR-pprM/pprI transgenic group were higher than that of the control group,and the deformity rate was lower than that of the control group.2.Targeting of pprM and pprI genes can significantly improve the resistance of Drosophila to MMC.When mitomycin reached 80 ?g/mL,the survival,climbing and fertility of pprM/pprI transgenic flies were higher than those of the control group.The pprM and pprI genes can exert anti-MMC functions by increasing the activity of Drosophila antioxidant enzymes.