Changes in Extra Bristles in a Population of Drosophila Maintained by Isofemale Lines

Abstract

Fifty-five isofemale lines of Drosophila melanogaster that revealed a high phenotypic variation in dorsocentral and scutellar extra bristles have been maintained for 23 generations. Although the mean penetrance and positional specificity of the extra bristles have not changed in the population as a whole, significant changes have been observed in most Individual isofemale lines. The genetic determination of the number and position of extra bristles is discussed.