Figure 4. Distinct enhancers regulate tsl expression in the prothoracic gland and in the ovarian follicular epithelium.

(A) The tsl gene and fragments tested for enhancer activity¹⁰. Red and orange rectangles are translated and untranslated exons respectively. The triangle is the P element in tsl⁰⁶¹⁷. Blue rectangles are the fragments in the in vivo enhancer assay. Dark orange rectangles show the identified enhancers, PG for the prothoracic gland and O for the ovaries (for expression in ovaries see10). (B) Expression of the P-enhancer trap tsl⁰⁶¹⁷ is detected in the PG (arrowhead). (C–E) While tsl(3B) drives lacZ expression in the PG, tsl(3A) and tsl(B) do not (arrowheads).