Misexpression of unc-5Scer\UAS.cKa throughout the PNS under the control of Scer\GAL45-40 results in disruption of sensory input patterns. Whie the sensory axons project normally within the peripheral nerves to the CNS, once they arrive they fail to grow towards the midline and tend to stall laterally, or in some cases fail to enter the CNS altogether. Despite the disruption of the sensory input, the overall structure of the CNS appears normal, although subtle secondary defects would not be detectable. Expression of unc-5Scer\UAS.cKa phenocopies the effects of inhibiting the neurons and results in propagation defects in the crawling pattern.
Both ventral nerve cord commissures are absent in every segment of embryos expressing unc-5Scer\UAS.cKa under the control of Scer\GAL41407.
The axons of sensory neurons that express Scer\GAL4ato-NP6558 normally arborise in the intermediate region of the longitudinal connective when they enter the central nervous system (CNS). When these axons are forced to express unc-5Scer\UAS.cKa via Scer\GAL4ato-NP6558, they terminate instead lateral to the connective.
When unc-5Scer\UAS.cKa is expressed in embryonic salivary glands, driven by Scer\GAL4prd.RG1, the glands become oriented laterally away from the CNS midline, instead of lying parallel to it as in wild type. This phenotype has 70% penetrance.
In the ventral nerve cord of stage 16 unc-5Scer\UAS.cKa; Scer\GAL4eg-Mz360 embryo, serotonergic neurons fail to cross the midline. In addition, as subset of these neurons lose their serotonin uptake ability. The cell bodies of serotonergic neurons in the ventral nerve cord of stage 16 unc-5Scer\UAS.cKa; Scer\GAL4eg-Mz360 embryos are shifted laterally compared to wild-type.
Embryos expressing unc-5Scer\UAS.cKa under the control of Scer\GAL4gcm.PP show a block in the medial migration of longitudinal glia and an excess of glia migrating to the lateral edge of the central nervous system and onto the nerve roots.
When expression is driven by Scer\GAL4elav.PLu commissures are completely lacking from the embryonic CNS, because the commissural axons are prevented from crossing the midline.