Fig. 6. Transverse nerve phenotypes in beat Ic mutants. (A) An abdominal segment in a wild-type stage late 16 embryo that shows the TNs growing on the segment boundaries on either side. The TN is fully developed by this stage, and the LBD axon has tightly fasciculated with the TMN axon (large arrow). The TMN axon can sometimes be seen innervating muscle 25 at this stage (small arrow). (B) An abdominal segment in a beat Ic mutant (Df(2L)TE35D-GW19/Df(2L)RM5) embryo at stage late 16, showing TN fasciculation defects (arrows). The TMN axon and the LBD axon are both wandering onto the surface of the ventral muscles instead of fasciculating with each other. (C) Another abdominal segment in a beat Ic mutant embryo. The TMN and LBD axons appear to be growing right past each other (arrow). The TN growing on the adjacent segment boundary is relatively normal.
