Photophysical Factors Preliminary Study On The Impact Of Early Embryonic Development Of Toad

Laser and ultraviolet belong to nonionization radiation and have many biological effects.The main biological effects of laser are photochemical interaction,thermal interaction and electromagnetic effect.Ultraviolet(UV)may induce structure of DNA,produce cyclobutane pyrimidine dimmer and pyrimidine(6-4)pyrimidone photoproducts and result in immunosuppression so much as to cancer.In order to examine the effects of irradiation of laser and UV on amphibian's embryos,Bufo bufo gargarizans's embryos were explored to YAG double-frequency laser microbeams and lamps of UVB at various strength and time.Compared to the control groups,the embryos which were irradiated by laser or Ultraviolet B(UVB)had many changes in morphology,nucleic acid and proteins.When Bufo bufo gargarizans's two-cell stage embryos were irradiated by UVB at various wave strength and time,many kinds of abnormal embryos could be observed in treatment groups.The results indicated that after exposed at low strength and short time,such as 30μW/cm~2 by 20s,60s and 80μW/cm~2 by 20s,60s,120s respectively,embryos' development process was promoted and death rate and degree of deformities were reduced than control and other groups. On the contrary,after irradiated by high wave strength and long time,such as 80μW/cm~2 by 600s and 100μW/cm~2 by 20s,60s,600s and 120μW/cm~2 by 20s respectively,embryos' death rate was higher than control and other groups.The results suggested that UVB had two sides of effect on Bufo bufo gargarizans's embryos,one is biostimulating and the other is killing and wounding.After irradiated by UVB with same time but various wave strength,the four-cell stage embryos,gastrulae and neurula were fetched and the results of DNA and RNA gel electrophoresis showed that the higher wave strength and the more dispersion.A new method,single-cell gel electrophoresis(comet assay),was used to determined damage grade of DNA after mouse's lymphocytes were irradiated by laser.The results indicated that high intensity laser led to severe damage of DNA.Changes of gastrula protein's expression patterns between control groups and other groups which were irradiated by YAG laser were examined by two-dimensional electrophoresis.The map of proteins showed that protein expression was influenced by laser irradiation and the total number of protein spots was related to the intensity of the laser beam.There were some proteins obviously changed in laser treatment groups compared to the control and some spots were visible in the treatment groups but not observed in the control. In further reserch,it is necessary to proceed to point out which genes and proteins change after irradiation with laser and UVB.This basic reaserch could offered reference to environmental biology.