Biomaterial Database

Adaptation of Drosophila melanogaster populations to high mutation pressure: evolutionary adjustment of mutation rates. 1987

H Nöthel

Evolutionary aspects of high mutation pressure were studied in laboratory populations of Drosophila melanogaster that have irradiation histories up to 600 generations. Dose-response regressions for the x-ray induction of various types of mutation were obtained from six of these populations. The sensitivity of these irradiated populations relative to an unirradiated control population was characterized by dose reduction factors. Sensitivity decreased stepwise with the stepwise increase in irradiation levels to which the populations had been exposed every generation (0 R, 2 kR, 4 kR, 8 kR; 1 R = 0.258 mC/kg) but remained the same over hundreds of generations when the irradiation levels were constant. Resistance is controlled by single genetic factors. Additional factors evolved in subpopulations exposed to increased irradiation levels, and different factors evolved in populations that were kept separate from the beginning of their irradiation histories. Two of three factors persisted in subpopulations no longer irradiated, but one factor disappeared; this last one behaved like a transposon. Factors of relative radio-resistance are stage specific (immature oocytes) and some of them are assumed to modify or control mutation-rate genes. The resistance factors enable populations to achieve an equilibrium between the amounts of environmental mutagens and intrinsic mutation rates.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D011832	Radiation Injuries	Harmful effects of non-experimental exposure to ionizing or non-ionizing radiation in VERTEBRATES.	Radiation Sickness,Radiation Syndrome,Injuries, Radiation,Injury, Radiation,Radiation Injury,Radiation Sicknesses,Radiation Syndromes,Sickness, Radiation,Sicknesses, Radiation,Syndrome, Radiation,Syndromes, Radiation
D011836	Radiation Tolerance	The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.	Radiation Sensitivity,Radiosensitivity,Sensitivity, Radiation,Tolerance, Radiation,Radiation Sensitivities,Radiation Tolerances,Radiosensitivities,Sensitivities, Radiation,Tolerances, Radiation
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D005075	Biological Evolution	The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.	Evolution, Biological
D005260	Female		Females
D005821	Genetic Techniques	Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.	Genetic Technic,Genetic Technics,Genetic Technique,Technic, Genetic,Technics, Genetic,Technique, Genetic,Techniques, Genetic
D000222	Adaptation, Physiological	The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.	Adaptation, Physiologic,Adaptations, Physiologic,Adaptations, Physiological,Adaptive Plasticity,Phenotypic Plasticity,Physiological Adaptation,Physiologic Adaptation,Physiologic Adaptations,Physiological Adaptations,Plasticity, Adaptive,Plasticity, Phenotypic