Coordinate expression of human and murine CD34 RNA in human CD34 transgenic mice and human tissues.

(A-B) Northern blot analysis of human transgenic and endogenous murine CD34 in tissues of mice from 2 different founder lines. (A) Line 14. (B) Line 29. A quantity of 20 μg total RNA was loaded for each lane and hybridized with a 0.5-kb probe from the 3′ enhancer of the humanCD34 gene,21,40 stripped and rehybridized to a 1.26-kb fragment generated by digestion of murine CD34 cDNA7 with PstI and XhoI, and then finally to a GAPDH probe to control for relative loading. Rat 1a cells served as a negative control, and human KG1a cells served as a positive control for human CD34.39 The human and murine CD34 probes do not cross-hybridize with RNA from the other species under stringent conditions.21 Bladder, heart, lymph node, and lung show the highest levels of expression for both genes. (C) The human CD34 and GAPDH probes were successively hybridized to a human tissue mRNA blot (Clontech).