eIs2137 [sup-7(+) + Dm-hsp::lacZ] IV. lacZ expression induced by heat shock. Limited pattern (the pSHZ1 vector was originally designed for use in Drosophila, not C. elegans, and is not the best vector for expression of lacZ in the worm). This strain has predominantly historical value (as the first C. elegans strain shown to express a foreign gene). eIs2137 transgene is integrated and contains two plasmids: pAST (sup-7 amber suppressor), and pSHZ1 (lacZ driven by Drosophila heat shock promoter (S. Munro)).