The Influence of X-Rays and Near Infra-Red Rays on Recessive Lethals in Drosophila Melanogaster

Publisher Website
Google Scholar
Abstract
Supplementary treatment of the spermatozoa of D. melanogaster with near infra-red radiation does not effect any significant increase in the frequency of production by x-rays of recessive, sex-linked lethal mutations. Analysis of a sample of 100 of these lethals by the salivary gland chromosome method revealed that 32% were associated with gross chromosomal alterations. A consideration of these data and those obtained in previous expts. suggests that radiation-induced recessive lethals are not attributable primarily to a position effect dependent on the establishment of new associations by the gene concerned. Consideration of the combined data also suggests that near infra-red radiation, when used as a supplementary treatment, is effective in increasing the frequency of chromosomal rearrangements by facilitating recombination, presumably at the expense of restitution, among the ends of chromosomes broken by the ionizing radiation.