Expression of ABCA1 in BAC⁺ApoE^–/– mice. Increased ABCA1 protein was detected in the liver, kidney, brain, aorta, gonad, large intestine (lg. int.), and in peritoneal macrophage cells isolated from the BAC⁺ApoE^–/– mice (a). An anti-ABCA1 mAb raised against the second nucleotide-binding domain was used (top panel) to detect ABCA1. To ensure equal protein loading, the Western blots were probed with anti-GAPDH Ab (lower panel). (b) Human-specific ABCA1 transcript was detected in all tissues tested using RT-PCR. For each tissue, lane 1 is human specific, lane 2 is mouse specific, and lane 3 is an 18S control. The last panel is from a control mouse and contains no human transcript.