Genetic analysis of the wing vein pattern of Drosophila.

Of the many mutations known to affect the wing vein pattern we have selected the most extreme in 29 genes for study. Their phenotype can be classified in two major classes: lack-of-veins and excess-of-veins, and in several internally coherent groups. The study of multiple mutant combinations, within groups and between groups, reveals several genetic operations at work in the generation of the vein pattern. The finding that some of these mutations also affect cell proliferation in characteristic ways has prompted a generative model of wing morphogenetic and pattern formation based on cell behaviour properties defined by the corresponding wild-type genes.