Cell functions in morphogenesis: clonal analysis of new morphogenetic mutations in Drosophila melanogaster.

The behavior in mitotic recombination clones of 10 new EMS-induced morphogenetic mutations has been studied in several imaginal systems: wing, eye, and abdominal histoblasts. They have been classified into three major groups according to their phenotypes: Group I is composed of four mutations that cause the disappearance of the mutant cells late in the development of all of the imaginal systems tested. Group II is composed of two mutations that produce elongated clones in the wing disc but do not show any mutant effect in the other imaginal systems. Group III is composed of four mutations that yield bulged, whirled, or invaginated mutant cells in all of the imaginal systems tested. Working hypotheses concerning the possible cellular bases of these mutations are proposed.