pTG96 was constructed for the purpose of assessing the pattern of expression of sur-5
, a gene encoding a novel protein that was identified in a genetic screen for suppressors of a vulvaless phenotype associated with certain dominant-negative mutations in let-60Ras (Gu et al. 1998). The plasmid contains 7.3 kb of genomic DNA from the sur-5
locus and a vector, pPD95.70 (A. Fire, J. Ahnn, G. Seydoux and S. Xu, personal communication), whose expres- sion of GFP is dependent on the addition of heterologous DNA. The form of GFP encoded by the vector has a nuclear localization signal (A. Fire, personal communication) and an amino acid change (cysteine for serine at position 65) that increases the intensity of green fluorescence (Heim et al. 1995). Also, the DNA encoding GFP contains artificial introns for enhanced expression in transgenic C. elegans (A. Fire, personal communication). | pTG96 includes a 3.68-kb fragment of the 5-flanking sequence and the full-length sur-5
genomic sequence fused at its C terminus to GFP containing a potent, artificial nuclear localization signal (NLS) sequence.