Radiation-induced and transposon-induced chromosome damage in Drosophila: translocations and transmission distortion.
The possible interaction between X-ray- and transposon-induced chromosome damage was monitored in the P-M system of hybrid dysgenesis in Drosophila melanogaster. One- to two-day-old F1 dysgenic males originating from a cross between M strain females and P strain males were irradiated with 5.5 Gy (550 rad) or used as controls to monitor X-Y translocations and transmission ratio distortion. Two 3-day sperm broods were sampled for the former and two 4-day broods for the latter to detect damage induced in the most radiosensitive cells. F1 nondysgenic males derived from M female to M male crosses (controls) were treated identically. X-Y chromosome translocations induced by P element mobility alone declined sharply with a decrease in temperature (18 versus 21 degrees C) and they were significantly reduced with aging of hybrid males from brood 2, 4-8 days of age, to brood 3, 7-11 days of age. No significant increase in translocations was observed when X irradiation and P-M dysgenesis were combined, showing no interaction between damages induced by the two mutator systems. In contrast, interaction was observed in transmission ratio distortion which was significantly increased by X irradiation of hybrid males derived from both reciprocal M X P and P x M crosses. The preferential elimination of P element-bearing autosomes occurred when either spermatocytes or spermatids were irradiated. An aging effect was also observed, resulting in less distortion in 9- to 14-day-old dysgenic males compared to 5- to 10-day-old hybrids.
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Department of Microbiology and Immunology, New York Medical College, Valhalla 10595.
Wallace
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Margulies
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D000818:Animals; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000528:radiation effects*; D004249:DNA Damage; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D006824:Hybridization, Genetic; D008297:Male; D014178:Translocation, Genetic
D004251:DNA Transposable Elements