The few Ubqn1 germline clone eggs laid by otherwise Ubqn1 heterozygous females show morphological defects, including defective dorsal appendages, and do not develop.
Ubqn1 pre-pupae show severely reduced neuropil, head malformation and loss of head fat body, incomplete limb eversion, and impaired midgut histolysis.
Whole-eye Ubqn1 clones in adults raised in 12h:12h dark:light cycles show a significant and progressive decrease in electroretinogram amplitudes at days 15 and 45. They show progressive retina defects at days 15 and 30, but not at day 1; these include vacuolization, degeneration and loss of photoreceptors, glial death, split rhabdomeres and loss of rhabdomeres, electron dense aggregates, and mitochondria accumulation; at day 30 there is also an enlargement of synaptic terminals in the lamina. Individuals reared under constant darkness still show decreased electroretinogram amplitudes at day 45 and loss of photoreceptors at day 30. Transmission electron microscopy reveals that Ubqn1 clonal retina exhibit a significant increase in rough ER density in 1-day old adults, and a significant increase in autophagosomes, autolysosomes/amphisomes, as well as an accumulation of abnormal lysosomes, in 15-days old adults.
Ubqn1 clones in the larval fat body show abnormal lysosomes as compared to controls, namely a prominent increase in the number of Lamp1-GFP positive compartments despite of unaffected Lysotracker staining (marker of acidic lysosomes) at the second instar, aberrant/clustered Lamp1-GFP positive compartments and significantly decreased Lysotracker staining at the third instar, and a severe decrease in Lysotracker staining at the wandering third instar; at the third instar, Lysotracker and Lamp1-GFP puncta do not colocalize, indicating that most lysosomes are not acidified.
Ubqn1 clones in the third instar larval fat body also show abnormal autophagic flux compared, as compared to controls; there is a significant increase in autophagic vesicles (using mCherry-Atg8 or GFP-Atg8 reporters) and a significant increase in autophagosomes and non-acidic autolysosomes (using a GFP-mCherry-Atg8 reporter); there is also a significant decrease in acidic lysosomes and autolysosomes under both fed and starved conditions.
Ubqn1 clones in the third instar larval salivary gland show aberrant morphology and accumulation of endoplasmic reticulum (sqh-EYFP-ER marker).