Normalized expression patterns of the ɛ and Aγ human transgenes in mice carrying HS2ɛγ, HS3ɛγ, and HS3ɛγ^−1086Mut constructs. (A) HS2ɛγ: ɛ transgene expression patterns; (B) HS3ɛγ: ɛ transgene expression patterns; (C) HS3ɛγ^−1086Mut: ɛ transgene expression patterns; (D) HS2ɛγ: γ transgene expression patterns; (E) HS3ɛγ: γ transgene expression patterns; (F) HS3ɛγ^−1086Mut: γ transgene expression patterns. For all lines, expression data are expressed relative to the peak (maximal) expression level, which is taken as 100%. Dashed lines represent yolk sac samples; solid lines represent fetal liver and postnatal samples. The identity of each transgenic line is given by the key provided in the box accompanying each set of curves. For (F) γ expression curves for the three transgenic lines that exhibit a phenotype after deletion of the −1086 bp YY1 site are shown with bold lines.