In the male C. elegans nervous system, the LOV-1-PKD-2 transient receptor potential polycystin (TRPP) receptor-channel complex localizes to ciliated endings of sensory dendrites. In humans, the polycystins localize to cilia of renal epithelia cells, and mutations in the TRPP genes PKD1 and PKD2 cause autosomal dominant polycystic kidney disease. In male worms, GFP-tagged PKD-2 localizes to cell bodies and cilia of CEM, RnB and HOB neurons, and can be visualized as moving puncta in dendrites. When PKD-2 and LOV-1 are absent, males exhibit response and location of vulva (Lov) defects. The kinesin-3 KLP-6 is required for normal localization of PKD-2 as well as male response and vulva location behavior. We previously screened for mutants exhibiting mislocalization of PKD-2::GFP1. In the ciliary localization (Cil) defective mutant
my16, we observe an abnormal accumulation of PKD-2::GFP in the ciliary base and cilium proper of CEM neurons, though the dendrites had normal localization of PKD-2::GFP1.
my16 males are response and Lov defective, presumably due to the mislocalization of PKD-2. We are interested in identifying the gene mutated in
my16 animals and understanding its function in ciliary receptor trafficking and male mating behaviors. In wild-type males, KLP-6::GFP is expressed in both the CEM and IL2 neurons and localizes throughout the neuron. In contrast,
my16 mutant males display abnormal localization of KLP-6::GFP in the form of both globular structures and small puncta located laterally along the ciliary ending of the CEMs. One possibility is that KLP-6 is trapped on its cargo as indicated by the puncta. In hermaphrodites, which contain IL2 and lack CEM neurons, KLP-6 localization appears wild type. We conclude that the
my16 allele affects KLP-6::GFP localization only in CEMs, and are currently determining whether the
my16 mutation specifically affects male sensory neurons. Motor-based transport is important for precise cargo delivery, and we are interested in determining how the
my16 mutation affects the KLP-6 motor and its cargo PKD-2. To test the interdependence between
pkd-2,
klp-6, and
my16, we will examine KLP-6::GFP localization in a
pkd-2;
my16 double mutant background, and PKD-2::GFP localization in a
klp-6;
my16 double mutant background. We will also study the effects of
my16 on male ciliated neuronal development and function, including examination of genetic interactions between
lov-1,
pkd-2,
klp-6, and
my16 on male mating behaviors. 1. Bae YK, Lyman-Gingerich J, Barr MM, Knobel KM. 2008. Identification of genes involved in the ciliary trafficking of C. elegans PKD-2. Dev Dyn.