Heterozygous effects of irradiated chromosomes on viability in Drosophila melanogaster. [X radiation]

Journal Article · Fri Oct 01 04:00:00 EDT 1976 · Genetics; (United States)

OSTI ID:7342691

Simmons, M J

Two large experiments were conducted in order to evaluate the heterozygous effects of irradiated chromosomes on viability. Mutations were accumulated on several hundred second chromosomes by delivering doses of 2,500R over either two or four generations for total x-ray exposures of 5,000R or 10,000R. Chromosomes treated with 5,000R were screened for lethals after the first treatment, and surviving nonlethals were used to generate families of fully treated chromosomes. The members of these families shared the effects of the first irradiation, but differed with respect to those of the second. The chromosomes treated with 10,000R were not grouped into families since mutations were accumulated independently on each chromosome in that experiment. Heterozygous effects on viability of the irradiated chromosomes were tested in both isogenic (homozygous) and nonisogenic (heterozygous) genetic backgrounds. In conjunction with these tests, homozygous viabilities were determined by the marked-inversion technique. This permitted a separation of the irradiated chromosomes into those which were drastic when made homozygous and those which were not. The results indicate that drastic chromosomes have deleterious effects in heterozygous condition, since viability was reduced by 2 to 4 percent in tests performed with the 10,000R chromosomes, and by 1 percent in those involving the 5,000R material. Within a series of tests, the effects were more pronounced when the genetic background was homozygous. These results suggest that the mutants induced by high doses of x-rays are principally drastic ones which show deleterious effects on viability in heterozygous condition.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 7342691
• Journal Information: Genetics; (United States), Journal Name: Genetics; (United States) Vol. 84:2; ISSN GENTA
• Country of Publication: United States
• Language: English

Related Subjects

560153* -- Radiation Effects on Animals-- Invertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
ARTHROPODS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CHROMOSOMES
DOSE-RESPONSE RELATIONSHIPS
DROSOPHILA
ELECTROMAGNETIC RADIATION
FLIES
FRUIT FLIES
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
INSECTS
INVERTEBRATES
IONIZING RADIATIONS
MUTATIONS
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
X RADIATION