Fig. 4. The lin-48 promoter contains two redundant elements important for lin-48 expression in hindgut cells. lin-48 sequences were tested for their ability to drive expression of GFP, and are diagrammed using the conventions of Fig. 2A. Transgenes containing the mutant sequences illustrated in Fig. 5 are indicated with X. The percentages of cells expressing GFP (black bar), expressing very low but detectable levels of GFP (gray bar) or not expressing GFP (white bar) are indicated for each construct. n, number of animals scored for expression.