[Incorporation of 5-bromodeoxyuridine-6-3H in salivary gland cells of Drosophila virilis Sturt. during prolonged labeling].

: When rearing the D. virilis larvae on the nutrient medium with 5-bromodeoxyuridine-6-3H (3H-BDU) at different developmental stages, it was found that the intensity of isotope incorporation in the chromosomes and cytoplasm of the salivary gland cells depended on the duration of effect and concentration. The distribution of label along the chromosomes does not occur at random. The spectrum of isotope incorporation is specific for each chromosome. All regions which changed their puffing pattern as a result of rearing the larvae on the medium with 3H-BDU incorporated the isotope and the frequency of incorporation in the most of them differed reliably from the random one. The intensity of incorporation increased with the duration of labelling and the isotope concentration.