Figure 1.
cpx-1 Encodes the Worm Homolog of Complexin and Regulates Locomotion and Neurotransmitter Release (A)
cpx-1 is the complexin gene with the highest identity to mouse and fly complexins. C. elegans CPX-1 was aligned with mouse CplxI (AAH14803) and fly complexin (AAF69518) using ClustalW2. Percent identities were calculated using Jalview [33]. (B)
cpx-1 is expressed in the nervous system. Top: gene model and regions deleted in C. elegans complexin mutant alleles (red bars). The black line represents the region of the genome used to create the rescuing GFP construct. Gray triangle on transcript represents the 30UTR. GFP was inserted after the first three codons. Bottom: a reporter construct consisting of the
cpx-1 gene with GFP inserted at the N terminus of complexin is expressed in many neurons in the head and body of the animal. Neurons expressing
cpx-1 include the motor neurons of the ventral nerve cord, neurons in the head ganglia, and also neurons of the pharyngeal nervous system, including theMCand M4 motorneurons. The inset shows the punctate localization of GFP::CPX-1 along the dorsal nerve cord. Confocal images were taken of young adult hermaphrodites oriented dorsal up and anterior to the left. Images are a stitch of multiple confocal Z projections along the length of the animal. (C)
cpx-1 mutants are defective for thrashing in liquid.
cpx-1 thrashing behavior can be rescued by expressing
cpx-1 under a panneuronal promoter (Prab-3::
cpx-1 EG4633), but not by expressing it specifically in the acetylcholine neurons (Punc-17::
cpx-1 EG4713). Graph shows means and standard error of the mean (SEM) of the thrashing behavior. Tukey-Kramer multiple comparisons test: *p < 0.001. The n values for each strain are listed at the bottom of each bar. (D)
cpx-1mutants are hypersensitive to the acetylcholinesterase inhibitor aldicarb, indicating that excessive acetylcholine is released at neuromuscular junctions. This sensitivity can be rescued by expressing
cpx-1 in all neurons using the rab- 3 promoter. Graph shows means and SEM.