The genetic basis of somatic damage produced by radiation in third instar larvae ofDrosophila melanogaster

Summary Third-instar larvae of different genotypes were exposed to X-radiation of various doses, and survival was scored separately for the sexes and genotypes. Most of the observed correlations agree with the hypothesis that somatic radiation damage was exclusively or almost exclusively due to chromosome breakage followed by chromosome loss, cellular damage or death resulting whenever a portion of the genome was no longer represented in at least haploid condition. Monosomaty for either of the long autosomes does not appear to be detrimental to somatic cells. The detailed evidence has been summarized at the beginning of the discussion.Appendix: key to the symbols used above B Bar eyes - bw brown eye color - bw ^D brown eye color dominant - ct ^– cut deficiency - ct ⁱ cut insertion - ct ^l cut lethal - cn cinnabar - e ebony body color - f forked bristles - In En inversion entire - In 49 inversion 49 - N ⁸ notch 8, deficiency at the N locus - Px ² plexate 2 deficiency - sc ^S 1 inversion scute S1 - sn ^x 2 singed bristles - t ² tan 2 body color - v vermillion eyes - vg ^D vestigal depileate - X ^c 2 ring X-chromosome - Y Y-chromosome - y yellow With 5 Figures in the TextSubmitted to the faculty of the Graduate School in partial fulfillment of the requirements for the degree, Doctor of Philosophy in the Department of Zoology, Indiana University 1961, Bloomington, Indiana.