Assuntos
Sequência Conservada , Copépodes/genética , DNA/genética , Animais , Sequência de Bases , Genoma/genéticaAssuntos
Cromatina/genética , Cromatina/metabolismo , Deleção Cromossômica , Copépodes/genética , DNA/genética , DNA/metabolismo , Animais , Sequência de Bases , Clonagem Molecular , Hibridização in Situ Fluorescente , Modelos Genéticos , Dados de Sequência Molecular , Sequências Repetitivas de Ácido Nucleico/genética , Homologia de Sequência do Ácido NucleicoRESUMO
The dynamics of life span (LS) have been studied in successive generations of postirradiation and control groups of Drosophila melanogaster, strain D-32, after a single exposure to Co60 gamma-quantum irradiation. It has been shown using mathematical procedures that in all postirradiation generations, with one exception, survival curves retain their canonical shape. This is indicative of the unchangeable nature of LS distribution. The mean LS of the progeny of irradiated parents either coincides with control values or can be higher or lower. Moreover, single irradiation results in an altered time-scanning of LS variations in successive generations as compared with controls. The possible origin of LS instability is discussed.
Assuntos
Longevidade/efeitos da radiação , Animais , Drosophila melanogaster , Feminino , Raios gama/efeitos adversos , Masculino , Fatores Sexuais , Análise de SobrevidaRESUMO
The dynamics of life span (LS) and fecundity in Drosophila melanogaster, strain D-32, were analyzed in a series of successive generations. Highly reliable variations in both fitness components were found. On initial inspection the variations would be characterized as random or irregular wherein mean values differed up to threefold. The variance in longevity is greater in females than in males. By use of mathematical procedures we have shown a scale regularity in LS distributions for all generations. Such regularity, in spite of considerable differences in absolute values (mean and maximum LS), suggested that the origin of LS instability is nonrandom.
Assuntos
Drosophila melanogaster/fisiologia , Longevidade , Animais , Feminino , Fertilidade , Masculino , Mortalidade , Fatores Sexuais , Análise de SobrevidaRESUMO
The adaptive response (AR) in human lymphocytes in different experimental protocols was investigated. The AR was found to be present in cells pre-exposed to 3 cGy of X-rays in G0, G1 and S phase as well as with tritiated water (4 muCi/ml) when the 'challenge' dose was given in G2. There was no AR after prior exposure of the cells in S phase to secondary irradiation from 70 GeV protons. The AR was not observed after preliminary X-irradiation of the lymphocytes in G0 and G1 and 'challenge' irradiation in G1. Cells from 6 patients with Down's syndrome were tested. At least 5 of them did not show the AR. The AR is considered to be a phenomenon of the antimutagenic aftereffect.
