Fig. 5. Morphology of the karussell-mutant neurons. Individual neuroblasts were filled using the DiI methodology. (A,E) DiI-labeled lineages of neuroblasts NB 3-5 and NB 7-3 in a wild-type embryo. (A') Higher magnification of the dotted area in A. The arrowhead denotes the growth cone. (B,F) Camera lucida drawings of wild-type lineages of NB 3-5 and NB 7-3. (C,G) DiI-labeled lineages of neuroblasts NB 3-5 and NB 7-3 in a hemizygous kus-mutant embryo. (C') Higher magnification of the dotted area in C. The arrowhead denotes the enlarged growth cone in the kus mutant. (D,H) Camera lucida drawings of these preparations reveal principally normal projection patterns, but altered fiber morphology and enlarged growth cones. No ectopic crossing of the CNS midline was observed.