Ivashchenko N I, Grishaeva T M
Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.
Genetika. 2002 Oct;38(10):1351-6.
The mutagenic effect of low-dose gamma-irradiation was studied in Drosophila melanogaster systems of hybrid dysgenesis by estimating polytene chromosome rearrangements, recombination frequency, and viability at the embryonic and postembryonic developmental stages. A dose of gamma-irradiation which had no effect detectable by routine line crossing proved to significantly reduce the number of recombinants in the H-E and P-M systems and mortality at postembryonic stages. However, this combined effect was obtained if irradiation followed transposition, i.e., it depended on the application sequence of the mutagenic factors. The reverse order of the mutagenic treatment led to summation of the effects: as compared to either control, the frequencies of the dominant allele mutations as well as the larval and pupal mortality in F2 increased significantly (at the level of 99.9%). This allowed us to estimate the contribution of extremely low-dose gamma-irradiation into the mutagenic effect, which was impossible under routine conditions.
通过评估多线染色体重排、重组频率以及胚胎期和胚后期发育阶段的活力，研究了低剂量γ射线辐照在果蝇杂种优势发育系统中的诱变效应。常规品系杂交未检测到有影响的γ射线辐照剂量，却被证明能显著减少H-E和P-M系统中的重组体数量以及胚后期的死亡率。然而，这种联合效应只有在辐照紧跟转座之后才会出现，即它取决于诱变因素的应用顺序。诱变处理的顺序相反会导致效应累加：与对照组相比，F2中显性等位基因突变的频率以及幼虫和蛹的死亡率显著增加（达到99.9%的水平）。这使我们能够估计极低剂量γ射线辐照对诱变效应的贡献，而这在常规条件下是不可能的。
