Fig. 4.

1A-2 acts as an enhancer blocker. (Top) Structure of the P[y^1A-2] transposon. A DNA fragment containing 1A-2 (▿) was inserted between the upstream enhancers and promoter of a yellow gene in a P transposon (black boxes with P show P element ends). Symbols are described in Fig. 1. (Bottom) Phenotype of P[y^1A-2] flies. The average wing and body (W, B) pigmentation score in a WT [su(Hw)⁺] and mutant [su(Hw)^-] background is listed. A “+” indicates average level of pigmentation was slightly greater than that of the corresponding control.