The strain BX265 expresses the translational fusion waEx18
(acs-4p::ACS-4::GFP). The strain was constructed using PCR to amplify
the acs-4 genomic and promoter region (approximately 3 kb upstream
of the ATG start site) and cloned into the pPD95.79 vector in frame to
create a C terminal GFP fusion protein. The plasmid construct was
microinjected into N2 worms and GFP positive worms were selected
each generation to maintain the extrachromosomal array. Worms
were viewed by confocal microscopy as described in Section 2.