The 341 bp hsp-16.2 promoter region was recovered as a HindIII/BamHI fragment from expression vector pPD49.78, and ligated between the unique HindIII/BamHI sites of pGFP-TT. The pGFP-TT vector was derived from pTU61 by site-directed mutagenesis, and contains Ser65Thr and IIe167Thr mutations that increase the fluorescence of GFP.