A biochemical marker for detection or irradiated pupae of the oriental fruit fly (Dacus dorsalis)

A biochemical method for detecting a radiation sensitive protein marker in pupae of gamma irradiated larvae of the Oriental fruit fly (Dacus dorsalis) using SDS-polyacrylamide gel electrophoresis (SDS-PAGE) is presented. Third instar larvae were irradiated at 100 Gy using a 60Co dry gamma cell. SDS-PAGE protein profile analysis of pupae of the irradiated larvae revealed the absence of a specific protein band (ascribed to a gene product, Gs, of a putative radiation sensitive marker gene) in comparison to the protein profile of unirradiated control larvae. Absence of the Gs protein band from the electrophoretic gel profile was observed only in two-day-old pupae (day 3 post-irradiation) and even at a dose as low as 40 Gy. Thus, irradiation of immature (two-day-old) larvae at 100 Gy resulted in the subsequent absence of the Gs protein only after day 8 post-irradiation (three-day-old pupae), by which stage the pupae of the unirradiated larvae had already started to synthesize the Gs protein, as seen by the SDS-PAGE gel profile. The absence of this Gs protein band in the SDS-PAGE profile of pupae of the irradiated larvae could be used as a biochemical marker for establishing the efficacy or irradiation of the Oriental fruit fly. (author). 7 refs, 3 figs