Expression of Past1^{Scer\UAS.B.T:Avic\GFP} under the control of Scer\GAL4^GMR.PU leads to morphological defects of varying severity in the adult eye due to ommatidial fusion and in late pupal retinas high proportion of ommatidia contain abnormal number of rhabdomeres and in early pupal eyes about 9% of ommatidia have two R7 photoreceptors. Scer\GAL4^mirr-DE-driven expression results in abnormal number of cone cells (three or five instead of the regular four) as well as supernumerary inter-ommatidial pigment cells in some of the ommatidia.

Garland cells isolated from third instar larvae expressing Past1^{Scer\UAS.B.T:Avic\GFP} controlled by Scer\GAL4^da.PU show attenuation of endocytosis in an avidin internalization assay.