Fig. 11.

Principal cell mesh knockdown in the adult Drosophila Malpighian tubule does not alter Na⁺/K⁺-ATPase (NKA) expression and actin cytoskeleton. NKA is expressed in the basolateral membrane of the principal cells of a 14-day-old adult control female fly tubule main segment (w;tub-GAL80^ts20/+;c42-GAL4/+; A′′ and A′′′) and in the main segment of the tubule subjected to adult onset of principal cell mesh knockdown (w;tub-GAL80^ts20/UAS-mesh^RNAi;c42-GAL4/+; B′′ and B′′′) where Mesh expression at smooth septate junctions (sSJs) between the principal cells is greatly reduced and is mostly restricted to the stellate cells (B and B′′′). A′′′ and B′′′ show single-confocal plane images indicated by dashed-box areas in A′′ and B′′, respectively. F-actin staining in a control tubule main segment (C′–C′′′) is also similar to its staining in a mesh knockdown tubule main segment (D′–D′′′). C′′′ and D′′′ show single-confocal plane images indicated by dashed-box areas in C′′ and D′′, respectively. Nuclei were counterstained blue with DAPI. RNAi, RNA interference; SC, stellate cell. Ten samples per genotype were examined. Scale bars, 50 μm.