Fig. 3. Loss of Gba1b impairs glial morphology, which precedes neuronal loss.

(A) Loss of Gba1b leads to vacuolized glia. TEM images of fly retina of the indicated genotypes after 2 days of D/L cycles. Photoreceptor neurons are highlighted in orange, and pigment cells are highlighted in blue (a, a′, b, and b′). R, rhabdomeres. Red arrowheads point to lysosomes in pigment cells. y¹ w*; Gba1b^T2A-Gal4/Df null mutants exhibit an increased number of lysosomes in glia when compared to glia of y¹ w^* flies (b and b′). Magenta arrows indicate glial detachment, which is commonly seen in the retina of y¹ w*; Gba1b^T2A-Gal4/Df null mutants. Glial vacuoles are frequently seen in the retina of null mutant flies, and asterisks mark vacuoles in glia, which are rarely observed in y¹ w^* flies. (B) TEM images of fly retina of the indicated genotypes upon 7 days of D/L cycles. The overall morphology of the retina is severely affected in y¹ w*; Gba1b^T2A-Gal4/Df flies, whereas the retinas of y¹ w^* flies do not show obvious defects. The number of intact photoreceptors (PRs) per ommatidium is quantified on the right. Error bars represent SEM (n = 3); ****P < 0.0001. Flies that are tested in this experiment are phenotypically white.