Tau Regulates Endoreplication in Drosophila Malpighian Tubules

Endoreplication drives polyploidy in metabolically active epithelial tissues. Here we show that loss of <i>Drosophila</i> Tau increases nuclear size and DAPI fluorescence in principal and stellate cells of the Malpighian tubule, indicative of elevated DNA content. A similar increase is observed in the salivary gland, another polyploid tissue. These findings reveal a previously unrecognized role for Tau in restraining endoreplication in non-neuronal epithelia.