Expression of Nha1Scer\UAS.T:Avic\GFP-EYFP under the control of Scer\GAL4c42 results in higher basal levels of secretion in adult Malpighian tubules compared to controls. When the capa protein is added to the medium, the fluid secretion rate falls away to zero in Malpighian tubules expressing Nha1Scer\UAS.T:Avic\GFP-EYFP under the control of Scer\GAL4c42 (in contrast to wild type, where the fluid secretion rate increases in response to capa protein).