Variation of Scutellar Bristles in Drosophila XIII. Effects of Scute Alleles

Abstract

The BCI and 8C' alleles have been substituted for 8C+ in a number of lines selected for extra (supernumerary) scutellar bristles. The gene extra-vert, which causes a marked increase in the number of scutellar bristles, is either present or absent in these lines. The substItution of 8C for 8C+ results in the suppression of extra-vert and its modifiers (termed the j3-system), but does not markedly affect the modifiers of 8C+ (termed the a-system).