1D-1E;2B10;[1D-1E];[2B10-2B10];

The futsch allele P158 (FBal0118228) which was formerly described as a null allele, has been determined to be a relatively large chromosomal deletion affecting over a hundred genes, with breakpoints in 1D-E; 2B10.

In mutant larvae, 97% of the peripheral nervous system (PNS) neurons fail to develop their normal dendritic morphology. Axonal growth is also impaired, few axons grow normally into the central nervous system (CNS). Axonal pathfinding is not affected - axons appear to simply stop after growing some distance. In mutants, longitudinal connectives are reduced, also disruptions in motoneural connections are observed. In particular SNb nerves fail to reach muscle fibres 12 and 13. Motor neurons stall and fail to set up the correct innervation pattern in 89% of the segments.