ORGANIZING SPATIAL PATTERN IN LIMB DEVELOPMENT

Recent studies on the development of the legs and wings of Drosophila have led to the conclusion that insect limb development is controlled by localized pattern organizing centers, analogous to those identified in vertebrate embryos. Genetic analysis has defined the events that l ead to the formation of these organizing centers and has led to the id entification of gene products that mediate organizer function. The pos sibility of homology between vertebrate and insect limbs is considered in light of recently reported similarities in patterns of gene expres sion and function.