Fig 1.
The CP09 neuron in C. elegans.
(A) Schematic of the position of cell body and axon of CP09 in the pre-anal ganglion of the C. elegans male tail. Reprinted from [14] under a CC BY license, with permission from WormAtlas (https://www.wormatlas.org/), original copyright 2019. (B) A skeleton map of CP09. Dots indicate presynapses (pink), postsynapses (purple), and gap junctions (blue). Information of individual synapses is accessible at WormWiring (http://wormwiring.org/).
Fig 2.
The rol-6 co-injection marker causes an expressional artifact in CP09.
GFP expression in the male tail of transgenic worms injected with an empty GFP vector (pPD95.75) along with rol-6(su1006) plasmid (pRF4) (A) or ttx-3p::GFP plasmid (B). Exclusive CP09 expression was observed in seven out of 12 independent transgenic lines injected with GFP vector + pRF4 (7/12), whereas no CP09 expression was observed in 10 independent lines with GFP vector + ttx-3p::GFP (0/10). Asterisks indicate autofluorescence in the spicule. Scale bar, 20 μm.
Fig 3.
The rol-6 fragment of pRF4 is responsible for CP09 expression.
(A) Schematic of cloning procedure to identify a region of pRF4 plasmid responsible for CP09 expression. Either rol-6 or vector fragment was subcloned into the empty GFP vector pPD95.75 and the resulting plasmids were injected to generate transgenic worms. (B) CP09 expression was observed in all 12 independent transgenic lines injected with rol-6 fragment::GFP (12/12), whereas no CP09 expression was observed in nine independent lines with vector fragment::GFP (0/9). (C) Proposed model of homologous recombination between pRF4 plasmid and GFP constructs.