Figure 2.—

Highly efficient temporal control of FLP-out. Heat-induced FLP-out as indicated by GFP-to-tdimer2(12) switch in a male worm of the genotype naEx40[P_hsp-16.41∷FLP, P_ceh-22∷GFP]; naEx56 [P_rpl-28<GFP<tdimer2(12)] (see Tables 1 and 2 and materials and methods for details on constructs and strains). (A–D) Worm before heat shock. Worm was raised at 25°, heat-shocked for 2 hr at 33°, and returned to 25° for 24 hr. (E–H) Same individual worm as in A–D after heat shock. All images were captured at 400× magnification. A and E, DIC; B and F, green channel; C and G, red channel; D and H, merges of DIC, green, and red panels above. Cells that no longer express GFP and only express tdimer2(12) are indicated by arrowheads in G. Bar, 50 μm. Note that tdimer2(12) was readily visible in worms grown at 25° but variably visible in worms grown at 15° and 20°.