Genetic fixation of phenotypic response of an ultrastructural character in the anal papillae of drosophila melanogaster

Abstract

The size of the apical folds of the plasmalemma in the cells of anal papillae of Drosophila melanogaster larvae is dependent on the osmotic pressure of the external medium. Increasing salt concentration of the external medium causes a decreasing size of the apical folds. This reaction could be genetically changed by selection on stretched anal papillae in pupae. This deviant character was correlated with a decreasing size of the apical folds, which even completely disappeared when extreme expression of the stretched character is obtained. © 1988, The Genetical Society of Great Britain.