Variation of scutellar bristles inDrosophila: XI. Selection for scutellar microchaetae and the correlated response of scutellar bristles

Abstract

The third chromosome mutant,hairy1, adds a varying number of microchaetae to the scutellum. The genetic relationship between this character and scutellar bristles was investigated using the conventional techniques of full- and half-sib analysis of variance and covariance, direct and correlated response to selection for microchaetae and scutellars respectively and diallel crosses at two stages in the programme. There was a good correspondence between the predicted and realized divergence resulting from selection for increased and decreased microchaetae. The correlated response in scutellar bristles appears to be accounted for primarily by genetic changes in microchaetae.