Deletion of human sequences from −18 to −10 kb and from +17 to +26 kb results in loss of RNA expression in transgenic mice.

(A) A diagram of XhoI-digested PAC54A19 construct. (B) Representative Northern blot analysis of 1 of 3 independent founder lines, as described in the legend to Figure 2. All 3 founders failed to express human CD34 in any tissue examined. Lane 9: heart RNA from one transgenic founder containing 141 kb of human CD34 genomic DNA (PAC88L2), as previously reported.23 24