Verification of deletion of Ey and βh1 promoters and associated loss of expression. (A) Southern blot strategy to differentiate WT diffuse, ΔEyhygro, and ΔEy mice. The open box is the PGK-hygro-selectable marker. Sites for the restriction enzyme ScaI are marked by S. (B) ΔEy Southern blot. Lane 1, D/D; lane 2, S/S; lane 3, ΔEyhygro/S; lane 4, ΔEyhygro/ΔEyhygro; lane 5, ΔEy/D; lane 6, ΔEy/ΔEy. (C) Representative RT-PCR assay of yolk-sac Ey expression in WT D/S mice (WT) and ΔEy/S (ΔEy) mice. Expression from D and S alleles is labeled. (D) Southern blot strategy to differentiate WT diffuse, Δβh1neo, and Δβh1 mice. The open box is the PGK-neo-selectable marker. Sites for the restriction enzyme NsiI are marked by N. (E) Δβh1 Southern blot. Lane 1, D/D; lane 2, S/S; lane 3, D/S; lane 4, Δβh1neo/S; lane 5, Δβh1/D; lane 6, Δβh1/Δβh1. (F) Representative assay of yolk-sac βh1 expression in WT D/S mice (WT) and Δβh1/S (Δβh1) mice. Expression from D and S alleles is labeled.