Retinal degeneration and sparse signs of brain vacuolation were detected in Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}/+ and Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}/Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG} (all under the control of Scer\GAL4^GMR.PF) flies. There is no obvious histological pathology in the thorax in muscles or other tissues. The exception is the fat body, which appears hypotrophied and contains, in older mutant flies, intracellular, acidophilic inclusions of rounded or ovoid shape and up to several microns in size. This results in decreased size, fewer lipid droplets and empty spaces which by shape and size suggests missing fat body cells. In the thoracic fat body of old Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}/Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG} flies display large cytoplasmic aggregates that are enclosed by a membrane, similar to other protein granules usually stored in this tissue. These aggregates are exclusively restricted to the fat body cells of old mutant flies and correlate with enlarged rough endoplasmic reticulum cisternae and frequently with apoptotic nuclei.

Empty spaces, corresponding in shape and size to single ommatidia, are defected in the retina of young Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}/Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}-Scer\GAL4^GMR.PF flies. This advances markedly in old mutant flies and most ommatidia appear disrupted or missing. At the stage of massive retinal degeneration the few remaining photoreceptors have none or only few and short microvilli.

Arrays of nanofilaments 7-9nm in thickness and nanospheres of about 20nm in diameter are abundant in the cytoplasm of glial cells that cover the surface of the retina (subretinal glia) and those that cover the surface of the brain (perineurial glia) in Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}/+ and Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG}/Hsap\TTR^{A.Scer\UAS.T:Zzzz\FLAG} (all under the control of Scer\GAL4^GMR.PF) flies but not in wild-type flies.