Gene-environment interactions of theeyelessmutant inDrosophila melanogaster

Abstract
A method is described for quantifying the phenotypic expression ofeyelessusing gauged estimates of the mean and standard deviation of the distribution of facet numbers.Gene-environment interactions of foureyelessallelesey,ey2ey4andeyKare compared in different genetic backgrounds and on a standardized Pacific background. The original strains differ in mean phenotypic value and in direction of response to variations in the ribonucleic acid content of the larval culture medium, whereas the four Pacific strains are more concordant. Consequently these differences are in part attributable to modifier genes present in the different genetic backgrounds of the original strains. Modifier genes also influence the periods in development at whicheyelessis sensitive to nutritional treatments.On the standardized Pacific background deficiencies of cholesterol cause an increase, whereas deficiencies of RNA or thiamine cause a decrease in the expressvity of all foureyelessalleles, but non-identity of their interaction profiles over an array of different suboptimal environments suggest that they may form a group of heteroalleles.