"pgTat" is a subgenomic construct from HIV-1 used to study Rev function in export of intron-containing viral RNA (see Malim et al., 1989. Nature 338:254 ). In the absence of Rev, this construct expresses the full length HIV-1\Tat protein under the control of UASp. In the presence of Rev, it expresses a truncated HIV-1\Tat protein under the control of UASp.