Quadruple or quintuple co-expression for one week during adulthood of Ras85DV12.cUa.UAS, p53VDRC.cUa, PtenGD13500, ApcVDRC.cUa and/or MedVDRC.cUa under the combined control of Scer\GAL4byn-Gal4, Dicer-2 (for efficient RNAi) and Gal80[ts] (for the temporal control of expression) leads to multilayered epithelia that form bulges at discrete points along the hindgut (only in animals that contained Ras85DV12.cUa.UAS and ApcVDRC.cUa together) and to an expanded pylorus (observed in the quintuple and all quadruple conditions that carried Ras85DV12.cUa.UAS); the quadruple co-expression conditions Ras85DV12.cUa.UAS+p53VDRC.cUa+PtenGD13500+MedVDRC.cUa and p53VDRC.cUa+PtenGD13500+ApcVDRC.cUa+MedVDRC.cUa do not lead to multilayering.
All quadruple and quintuple co-expression conditions - with the exception of the quadruple p53VDRC.cUa+PtenGD13500+MedVDRC.cUa+ApcVDRC.cUa - result in numerous hindgut cells losing their characteristic epithelial shape to assume a more mesenchymal appearance (processes extending towards the basement membrane and surrounding muscle layer), migrate locally and disseminate to distant sites in the organism (e.g. head, legs, fat body, ovaries, below the epidermis of the abdomen and within the abdominal cavity). Similar hindgut cell dissemination is observed upon the triple expressions of Ras85DV12.cUa.UAS+p53VDRC.cUa+PtenGD13500, Ras85DV12.cUa.UAS+ApcVDRC.cUa+PtenGD13500 or Ras85DV12.cUa.UAS+p53VDRC.cUa+ApcVDRC.cUa, the double expressions of Ras85DV12.cUa.UAS+p53VDRC.cUa, Ras85DV12.cUa.UAS+PtenGD13500 or Ras85DV12.cUa.UAS+ApcVDRC.cUa, all of which are more severe than upon the single expression of Ras85DV12.cUa.UAS alone.
The expression for one week during adulthood of p53VDRC.cUa, alone or together with PtenGD13500 or ApcVDRC.cUa, under the combined control of Scer\GAL4byn-Gal4, Dicer-2 (for efficient RNAi) and Gal80[ts] (for the temporal control of expression) does not affect the replication of cells (i.e. BrU-positive) in the pylorus, as compared to controls.