Open Close
Merianda, T.T., Botta, V., Bhat, K.M. (2005). Patched regulation of axon guidance is by specifying neural identity in the Drosophila nerve cord.  Dev. Genes Evol. 215(6): 285--296.
FlyBase ID
Publication Type
Research paper

Within an axon bundle, one or two are pioneering axons and the rest are follower axons. Pioneering axons are projected first and the follower axons are projected later but follow a pioneering axon(s) pathway. It is not clear whether the pioneering axons have a guidance role for follower axons. In this paper, we have investigated the role of Patched (Ptc) in regulating the guidance of medial tract, one of the longitudinal tracts in the nerve cord. In patched mutants the medial longitudinal tract fails to fasciculate on its own side along the nerve cord, instead it abnormally crosses the midline and fasciculates with the contralateral tract. Interestingly, the medial tracts cross the midline ignoring the axon-repellant Slit on the midline and Roundabout on growth cones. The medial tract is pioneered by neurons pCC and vMP2. Our results show that guidance defects of this tract are due to loss and mis-specification of vMP2, which results in the projection from pCC to either stall or project outward near the location of vMP2. Thus, both pioneering neurons are necessary for the proper guidance of pioneering and follower axons. We also show that the loss of Ptc activity in the neuroectoderm prior to the formation of S1 and S2 neuroblasts causes the majority of axon guidance defects. These results provide insight into how mis-specification and loss of neurons can non-autonomously contribute to defects in axon pathfinding.

PubMed ID
PubMed Central ID
Associated Information
Associated Files
Other Information
Secondary IDs
    Language of Publication
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Dev. Genes Evol.
    Development genes and evolution
    Publication Year
    Data From Reference
    Alleles (11)
    Genes (16)
    Natural transposons (1)
    Insertions (1)
    Experimental Tools (1)
    Transgenic Constructs (5)