Adulthood-specific expression of tkvGD2549 under the combined control of Scer\GAL4esg.PU and Scer\GAL80Su(H).GBE (together with Gal80[ts] for the temporal regulation of expression) prevents re-establishment of quiescence (phospho-H3)in the adult gut upon Ecc15 bacterial infection, leading to dysplasia 2 days after infection; upon Pseudomonas entomophila infection, there is an increase in gut barrier dysfunction (in Smurf assays) and increased mortality, as compared to controls.
Adulthood-only expression of tkvGD2549 under the combined control of Scer\GAL4esg.PU and Gal80[ts] (induced by temperature shift from 18[o]C to 29[o]C) leads to the adult posterior midgut showing increased numbers of intestinal stem cells and enteroblasts (i.e. esg-, Dl- and GBE+Su(H)-positive cells), but no changes in the numbers of enteroendocrine cells, and showing increased mitotic index (pH3-positive cells), as compared to controls; the size of the polyploid cells expressing tkvGD2549 is smaller than fully differentiated enterocytes, indicating a defect in maturation.
In wild-type flies, the pH of the anterior and posterior midgut are over 4.6, while in the copper cell region the pH is less than 3.0. In flies expressing tkvGD2549 under the control of both Scer\GAL80ts.αTub84B and Scer\GAL4esg-NP5130, the pH is uniformly above 4.6 throughout the midgut, demonstrating that functional copper cells are not made.
Expression of tkvGD2549 under the control of Scer\GAL4GMR24H06 for 8 days leads to a dramatic increase in mitotic cell numbers in the posterior midgut as compared with sibling co
Expression of tkvGD2549 under the control of Scer\GAL4Myo31DF-NP0001 has no effect on mitotic cell numbers in the posterior midgut as compared to sibling controls.
Adults expressing tkvGD2549 under the control of Scer\GAL4elav.PLu (in the presence of Dcr-2Scer\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.