Hox genes and the regulation of movement in Drosophila.

Many animals show regionally specialized patterns of movement along the body axis. In vertebrates, spinal networks regulate locomotion, while the brainstem controls movements of respiration and feeding. Similarly, amongst invertebrates diversification of appendages along the body axis is tied to the performance of characteristically different movements such as those required for feeding, locomotion, and respiration. Such movements require locally specialized networks of nerves and muscles. Here we use the regionally differentiated movements of larval crawling in Drosophila to investigate how the formation of a locally specialized locomotor network is genetically determined. By loss and gain of function experiments we show that particular Hox gene functions are necessary and sufficient to dictate the formation of a neuromuscular network that orchestrates the movements of peristaltic locomotion.