Expression of Dbx^Scer\UAS.fl under the control of Scer\GAL4^elav-C155 in all postmitotic neurons leads to a decrease in the ability of many neurons to extend axons. For example, 93% of hemisegments exhibit a significant decrease in motor axon projection into the periphery, with thinning or loss of the ISN nerve (within which U and RP2 motoneurons project axons), the SNc nerve (CoR motoneurons) and the SNb nerve (U and AC motoneurons). Thin and broken longitudinal connectives between neuromeres, as well as an occasional increase in the apparent size of the axonal scaffold within neuromeres, are found at 100% penetrance.