Garland cell nephrocytes expressing Gapvd1^KK105758 under the control of Scer\GAL4^pros.PMG show impaired function (i.e. they uptake significantly less albumin than controls), slit diaphragm defects (i..e slit diaphragm proteins appeared distorted; although slit diaphragms are formed properly at the surface, some appear ectopically, deeper in the labyrinthine channels) and labyrinthine channel defects (i.e. labyrinthine channels are dilated, fused, and protrude deeply into the cell).