Genetic control of the difference in male courtship sound between Drosophila virilis and D. lummei.

Abstract

The courtship sounds of five strains ofDrosophila virilis and three strains ofD. lummei were analyzed and the sounds of the two species were found to differ from each other by the number of pulses in a pulse train. The mean number of pulses in a pulse train varied from 5.8 to 9.1 inD. virilis and from 12.3 to 13.3 inD. lummei. TheD. virilis marker stockb, sv t tb gp2,cd, pe was crossed to the wild-typeD. lummei and the courtship sounds of reciprocal F1 hybrids and backcross hybrids were analyzed. Genes affecting the number of pulses in a pulse train were found to exist on each of the major autosomes but not on the X chromosome. The contributions of the second, third, fourth, and fifth chromosomes to the number of pulses in a pulse train were 0.513, 0.534, 0.430, and 0.841, respectively, the heterozygous condition increasing and the homozygous (both chromosomes fromD. virilis) decreasing the number of pulses in a pulse train by the number given. The interactions between chromosomes varied between 0.250 and −0.255. Thus genes causing the difference between the courtship sounds ofD. virilis andD. lummei are autosomal and the character truly polygenic.