Temporal analysis of Notch requirement for the specification of DA neurons in the larval central brain.

Shown are percentages of affected clusters in the larval central brain. Note that only removal of Notch function between St9–11 of embryonic development affects the specification of all TH-positive clusters, with the exception of DM2 cluster. Removal of Notch function at other stages has no significant effects on numbers of DA neurons in the clusters. This suggests that DA neurons in the hemispheres are born and specified early in embryonic development.