The following information accompanied stocks donated to the Bloomington Stock Center by Balaji Iyengar, Hamilton Health Sciences.
M{ChAT-DD.GAL4.VP16} expresses a fusion protein consisting of the GAL4 DNA-binding domain fused to the VP16 transcriptional activation domain under the control of a 7.3 kb segment upstream of ChAT (FBgn0000303). The GAL4-VP16 fusion protein is tagged at the N-terminus with the destabilization domain of human FKBP12 described in Banaszynski et al. (2006) "A Rapid, Reversible, and Tunable Method to Regulate Protein Function in Living Cells Using Synthetic Small Molecules", Cell 126: 995-1004. Iyengar's intention in building this construct was to express a GAL4-VP16 protein whose degradation could be controlled chemically by the Shield-1 small molecule inhibitor, but the destabilization domain appears to be ineffective with this particular construct.
M{ChAT-DD.GAL4.VP16}ZH-96E is an insertion into the M{3xP3-RFP.attP'}ZH-96E attP target site at 96E10,  3R:25697895..25697895  (R6). When this insertion was combined with P{10XUAS-IVS-GFP-WPRE}attP2, the expression of GFP showed a more restricted pattern than P{ChAT-GAL4.7.4}19B combined with P{w+mC=UAS-GFP.S65T}Myo31DFT2. This suggests that M{ChAT-DD.GAL4.VP16}ZH-96E more accurately reflects the expression of ChAT than the commonly used P{ChAT-GAL4.7.4}19B insertion, but a detailed comparison of ChAT expression to the GAL4 expression pattern produced by M{ChAT-DD.GAL4.VP16}ZH-96E has not been made.