The intestinal stem cells (ISCs) and enteroblasts (EBs) in the midguts of flies expressing Atac2^GD6972 under the control of Scer\GAL4^esg-NP5130 (restricted to two day post-eclosion onwards using Scer\GAL80^ts.αTub84B) are more densely distributed compared to wild type. The cells appear clustered rather than being scattered along the epithelium as single or paired cells. The number of ISCs in the most posterior part of the midgut is increased compared to controls. An increased number of mitotic cells (seen using PH3) is also seen compared to controls. The formation of ISC clusters is suppressed when the flies are fed the class I/II HDAC inhibitor Trichostatin A (TSA), and many of the ISCs are induced to produce differentiated enteroendocrine (EE) cells of enterocytes (ECs).

Midgut clones expressing Atac2^GD6972 under the control of Scer\GAL4^esg-NP5130 contain on average 3.5 cells, compared to 3.1 in controls. The number of intestinal stem cells in each clone is 3, compared to only 1.1 in the controls.

Adults expressing Atac2^GD6972 under the control of Scer\GAL4^elav.PLu (in the presence of Dcr-2^Scer\UAS.cDa to increase the efficiency of RNAi) do not show a significant defect in avoidance of noxious temperature (46[o]C) compared to control flies.

Expression of Atac2^GD6972 under the control of Scer\GAL4^elav.PLu (in the presence of Dcr-2^Scer\UAS.cDa to increase the efficiency of RNAi) results in viable flies or partial lethality, depending on the particular P{GD6972} insertion line used.