title: Age- and time interval-specific gamma radiation-induced DNA damage in adult maize weevils, Sitophilus zeamais Motschulsky, assessed using comet assays.
abstract: The gamma radiation-induced DNA damage in adult maize weevils, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), was assessed using single-cell electrophoresis (comet assay). Analysis of DNA damage following 0.5 and 1.0 kGy of gamma radiation was performed using cells from 1- and 15-day-old adults. Gamma-irradiated adults from both age groups showed typical DNA fragmentation, whereas cells from non-irradiated adults showed more intact DNA than young S. zeamais. Investigations using the comet assay showed that tail length, % tail DNA and % DNA damage all increased in adults of both age groups when compared to the control insects. A maximum comet length of 227.33 μm was recorded for 15-day-old adults at 24h after irradiation with 1.0 kGy and a minimum of 50.12 μm for 1-day-old adults at 0 h after irradiation with 0.5 kGy. The percentage of DNA damage increased up to 57.31% and 68.15% for 1- and 15-day-old adults, respectively, at 24h after irradiation with 1.0 kGy, whereas only 8.58% and 12.22% DNA damage were observed in the control batches. The results also showed that percentage of DNA damage increased at 24h after irradiation compared to that at 0 h. However, further studies are needed to confirm these results.
authors.affiliation: Laboratory for Stored Product Protection, Department of Zoology, Rajshahi University, Bangladesh. mmhbgd@yahoo.com
authors.forename: Md Mahbub
authors.initials: MM
authors.lastname: Hasan
authors.forename: Setsuko
authors.initials: S
authors.lastname: Todoriki
authors.forename: Akihiro
authors.initials: A
authors.lastname: Miyanoshita
authors.forename: Taro
authors.initials: T
authors.lastname: Imamura
mesh_terms: D000818:Animals; D020552:Comet Assay; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D012680:Sensitivity and Specificity; D013997:Time Factors; D048889:Weevils / Q000235:genetics / Q000528:radiation effects*; D003313:Zea mays / Q000469:parasitology*