Construct: mus209+tTa in which one of the two putative E2F binding sites upstream of the mus209 transcriptional start has been mutated (TATCCCGCtcaTTAGCCCG to TATCCCGCtcatTTctCaaG (binding site sequences in capitals)).
PCNAtΔsI rescues PCNAD-292/Df(2R)173
PCNAtΔsI partially rescues PCNA775/Df(2R)173