Two-color GFP expression system for C. elegans

We describe the use of modified versions of the Aequora victoria green flourescent protein (GFP)to simultaneously follow the expression and distribution of two different proteins in the nematode, Caenorhabditis elegans. A cyan-colored GFP derivative, designated CFP, contains amino acid (aa) substitutions Y66W. N146I, M153T and V163A relative to the original GFP sequence and is similar to the previously reported 'W7' form. A yellow- shifted GFP derivative, designated YFP, contains aa substitutions S65G, V68A, S72A and T203Y and is similar to the previously described '10C' variant. Coding regions for CFP flourescence spectra allowed visualization of the two distinct forms of GFP in neurons and in muscle cells. A series of expression vectors carrying FCP and YFP have been constructed and are being made available to the scientific community.