Induction of e^ypromoter-drivenneomycinmRNA expression from SCFA- and DMSO-induced MEL cell stable transfects. MEL cells, transfected with nested deletions of the embryonic ϵ^y promoter linked to the neomycin resistance gene (ϵ^y promoter, wt or mut, with or without HS2; Figure 1A) and stably selected as pools in G418-containing media, were induced to undergo adult erythroid differentiation in media containing 2% DMSO (▦) or 5 mM propionate (▨). The length, in base pairs, of the ϵ^y promoter in each construct is shown on the x-axis. The bar graph depicts fold-induction of neomycin mRNA expression, normalized to TPI mRNA and relative to neomycin expression from identical uninduced MEL transfects (□, set equal to 1). Pooled MEL cell transfects containing ϵ^y promoter only (ϵ^yneo constructs), HS2 plus ϵ^y promoter (HS2 ϵ^yneo constructs), and HS2 plus ϵ^y promoter with a mutated CACCC site (CACCCmut, HS2ϵ^ymut neo constructs) are as indicated. All results are from at least 3 independent pooled populations of transfects, except for HS2 -158 ϵ^yneo (n = 2) and HS2 -100 ϵ^yneo (n = 8). Error bars represent the standard error of the mean.