A WDR47 homolog facilitates ciliogenesis by modulating intraflagellar transport.

Cilia are conserved organelles found in many cell types in eukaryotes, and their dysfunction causes defects in environmental sensing and signaling transduction; such defects are termed ciliopathies. Distinct cilia have cell-specific morphologies and exert distinct functions. However, the underlying mechanisms of cell-specific ciliogenesis and regulation are unclear. Here, we identified a WD40-repeat (WDR) protein, NMTN-1 (the homolog of mammalian WDR47), and show that it is specifically required for ciliogenesis of AWB chemosensory neurons in C. elegans. NMTN-1 is expressed in the AWB chemosensory neuron pair, and is enriched at the basal body (BB) of the AWB cilia. Knockout of nmtn-1 causes abnormal AWB neuron cilia morphology, structural integrity, and induces aberrant AWB-mediated aversive behaviors. We further demonstrate that nmtn-1 deletion affects movement of intraflagellar transport (IFT) particles and their cargo delivery in AWB neurons. Our results indicate that NMTN-1 is essential for AWB neuron ciliary morphology and function, which reveal a novel mechanism for cell-specific ciliogenesis. Given that WDR47/NMTN-1 is conserved in mammals, our findings may help understanding of the process of cell-specific ciliogenesis and provide insights for treating ciliopathies.

Male pheromones modulate synaptic transmission at the C. elegans neuromuscular junction in a sexually dimorphic manner.

The development of functional synapses in the nervous system is important for animal physiology and behaviors, and its disturbance has been linked with many neurodevelopmental disorders. The synaptic transmission efficacy can be modulated by the environment to accommodate external changes, which is crucial for animal reproduction and survival. However, the underlying plasticity of synaptic transmission remains poorly understood. Here we show that in Caenorhabditis elegans, the male environment increases the hermaphrodite cholinergic transmission at the neuromuscular junction (NMJ), which alters hermaphrodites' locomotion velocity and mating efficiency. We identify that the male-specific pheromones mediate this synaptic transmission modulation effect in a developmental stage-dependent manner. Dissection of the sensory circuits reveals that the AWB chemosensory neurons sense those male pheromones and further transduce the information to NMJ using cGMP signaling. Exposure of hermaphrodites to the male pheromones specifically increases the accumulation of presynaptic CaV2 calcium channels and clustering of postsynaptic acetylcholine receptors at cholinergic synapses of NMJ, which potentiates cholinergic synaptic transmission. Thus, our study demonstrates a circuit mechanism for synaptic modulation and behavioral flexibility by sexual dimorphic pheromones.