Mosaic lethal mutations as one of the syndrome of hybrid dysgenesis due to the P element in Drosophila melanogaster

Abstract

Recessive lethal mutations were induced at an extremly high rate in the process of extracting the second chromosomes of D. melanogaster sampled from the Ishigakijima population. They were extracted by using the marked inversion stock (Cy/Pm) carrying the M type cytoplasm of the P-M hybrid dysgenic system. The mutation rate was estimated to be 0.090 per second chromosome per generation. This estimate is more than 18 times larger than the ordinary spontaneous mutation rate. The allelism rate between lines of lethal-carrying chromosomes was estimated to be 0.0012 and the average of the allelism rates within lines was estimated to be 0.43. Thus, it was concluded that the mosaic lethal mutations were induced during the spermatogenesis. Its erects on the estimates of some population-genetic parameters were discussed.