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DNA damage in early hamster embryos exposed to fluorescent light
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Theriogenology DNA DAMAGE IN EARLY HAMSTER EMBRYOS EXPOSED To FLUORESCENT LIGHT A. Okano, N. Saka, M. Takahashi and Y. Kanai Department of Animal Reproduction, National Institute of Animal Industry, Tsukuba, Ibaraki 305, Japan
Recently, some reports have indicated that mammalian embryos exposed to fluorescent light cause poor developmental ability proportionally to time of exposure. One of the putative effects of fluorescent light to embryos is DNA damage via reactive oxygen excited by an ultraviolet light from fluorescent lamp. We have previously reported a novel technique for detection of DNA damage in single hamster embryo by measuring a comet tail like electrophoretic pattern in microgel electrophoresis (comet assay). The objective of this research is to clarify DNA damage in embryos exposed to fluorescent light at the time of embryo collection. In addition, we tried to clarified a peroxidated condition in hamster embryos by fluorescent dye staining method. Golden hamsters (56 days of age) received a single injection of PMSG (30 units) to stimulate multiple follicle development. After 84h of PMSG administration, ovulation was induced with hCG(30 units) and then mated with same line male. Oviducts of female hamster which have copulation plug in next morning were flushed with HECM-1 for collecting embryos. Experiment 1: embryos were randomly assigned to :l) control (30 min in dark, n=25); 2) 5 min exposure (n=24); 3) 15 min exposure (n=27) and 4) 30 min exposure (n=24) in the drop of HECM-1 to usual fluorescent lamp (h=380-780 nm). Fragmented DNA of hamster embryos were detected by comet assay. To detect a peroxidated condition in hamster embryos by fluorescent lamp, embryos were stained with 2’,7’-dichlorodihydrofluorescein diacetate (DCHFDA). Embryos stained with DCHFDA were microscopically photographed and analyzed by an image analysis. Data were analyzed by Student’s t-test. The length of migrated DNA in hamster embryos were: 1) 24.0 c 4.1 t.tm (control); 2) 43.8 + 9.3 um (5 min); 3) 91.0 * 6.lunr (15 mm) and 4)145.1 + 12.9u.rrt (30 min), respectively. DNA damages significantly increased in embryos exposed to fluorescent light compared with that in control embryos (p
Theriogenology DNA DAMAGE IN EARLY HAMSTER EMBRYOS EXPOSED To FLUORESCENT LIGHT A. Okano, N. Saka, M. Takahashi and Y. Kanai Department of Animal Reproduction, National Institute of Animal Industry, Tsukuba, Ibaraki 305, Japan
Recently, some reports have indicated that mammalian embryos exposed to fluorescent light cause poor developmental ability proportionally to time of exposure. One of the putative effects of fluorescent light to embryos is DNA damage via reactive oxygen excited by an ultraviolet light from fluorescent lamp. We have previously reported a novel technique for detection of DNA damage in single hamster embryo by measuring a comet tail like electrophoretic pattern in microgel electrophoresis (comet assay). The objective of this research is to clarify DNA damage in embryos exposed to fluorescent light at the time of embryo collection. In addition, we tried to clarified a peroxidated condition in hamster embryos by fluorescent dye staining method. Golden hamsters (56 days of age) received a single injection of PMSG (30 units) to stimulate multiple follicle development. After 84h of PMSG administration, ovulation was induced with hCG(30 units) and then mated with same line male. Oviducts of female hamster which have copulation plug in next morning were flushed with HECM-1 for collecting embryos. Experiment 1: embryos were randomly assigned to :l) control (30 min in dark, n=25); 2) 5 min exposure (n=24); 3) 15 min exposure (n=27) and 4) 30 min exposure (n=24) in the drop of HECM-1 to usual fluorescent lamp (h=380-780 nm). Fragmented DNA of hamster embryos were detected by comet assay. To detect a peroxidated condition in hamster embryos by fluorescent lamp, embryos were stained with 2’,7’-dichlorodihydrofluorescein diacetate (DCHFDA). Embryos stained with DCHFDA were microscopically photographed and analyzed by an image analysis. Data were analyzed by Student’s t-test. The length of migrated DNA in hamster embryos were: 1) 24.0 c 4.1 t.tm (control); 2) 43.8 + 9.3 um (5 min); 3) 91.0 * 6.lunr (15 mm) and 4)145.1 + 12.9u.rrt (30 min), respectively. DNA damages significantly increased in embryos exposed to fluorescent light compared with that in control embryos (p