Genetic analysis of body color polymorphism in Drosophila melanogaster through selection experiment

Drosophila melanogaster is a widespread species that exhibits enormous variation in abdominal melanisation throughout its range. To gain insight into this variation, present work involves selection for abdominal melanisation. In 38 generations of selection for melanisation, an increase of ~2.5 fold in dark selected strain and a decrease of ~6-7 folds in light strain was observed in both the sexes as compared to control populations of D. melanogaster. Genetic crosses between dark and light strains obtained through selection produced intermediate offspring, but a clear maternal effect differentiated the reciprocal F1’s. F1 flies showed higher plastic effect as compared to selected dark and light strains across various growth temperatures. Our results are novel in the occurrence of five body color phenotypes in ratio of 1:4:6:4:1 (two-gene) in both sexes of D. melanogaster.