::gfp] translational fusion. To construct GFP fusion transgenes specifically expressed in DA9 neuron, an itr-1
pB promoter-driven vector modified with a gateway cassette (Invitrogen, Carlsbad, CA, USA) inserted at the Asp718I site just upstream of the GFP coding region was used. The sequence of C. elegans exp-2
isoform a cDNA was cloned into entry vector pDONR221 by PCR and BP reaction, and then transferred into a destination vector by Gateway recombination cloning LR clonase II (Invitrogen) reaction to generate an N-terminal fusion.