S1 nuclease analysis of transgene expression.

Tissues were harvested from transgenic embryos at 10.5, 12.5, and 14.5 days after conception. Yolk sac (YS) tissue was examined at 10.5 and 12.5 days, and fetal liver (FL) tissue was tested at 12.5 and 14.5 days. Bands corresponding to the galago (Gal) γ, human (Hum) γ, human ε, and mouse(Mus) α genes are labeled. Mouse ζ gene is not shown. Panels Ai and Aii are derived from analysis of transgenic lines 1 and 2 carrying the HS2-ε-^galγ transgene (diagrammed at top). Panel B is derived from analysis of line 187 carrying the HS2-ε-^humγ construct; these data are taken from work described earlier.4 Gels were subjected to PhosphorImager scanning, and the expression of the human ε and galago γ genes was determined as [transgene expression/(mouse ζ expression/2) + (mouse α expression/4)]/copy number.