Expression of human γ-globin in MEL cells.

RNAse protection assay showing murine α-globin (mu-α), human γ-globin (mu-γ), and GAPDH transcripts in MEL cells transduced with the I8Hβ/γW vector (containing the I8 and HS-40 enhancer elements and a β/γ hybrid gene) in lanes 2 to 5. Lanes 4 and 5 represent duplicate samples. Lane 1 shows sham-transduced MEL cells as a negative control for human γ-globin. Lane 6 represents the positive control derived from fetal liver RNA from a mouse transgenic for the β/γ hybrid gene. The transgenic founder of this mouse has been shown to express 20% human γ/total murine β-globin.29Lanes 7 to 9 represent in vitro transcribed unprotected probes (1/100 the amount used for protecting cellular RNA) concurrently loaded on the gel to show that the probe was in excess of the protected cellular RNA. The ratio of human γ-globin expression to murine α-globin (%), vector copy numbers, and expression normalized for copy number (expressed as hu-γ/total mu-α and hu-γ/copy of mu-α globin) are listed below each lane as a percentage.