Four-week old Df(3R)BSC499/Df(3R)MR22 mutant flies exhibit retinal degeneration. The retinas and rhabdomeres are indistinguishable from wild type at 1 day after eclosion, but show a loosening of the microvilli at 7 days. No photoreceptor loss is seen. An increased number of vacuoles is seen in the brains of 28-day old flies compared to age-matched controls. The axons of 1-day old flies are similar to controls but occasionally exhibit abnormal gaps between the axons. By 16 days, many more and larger extracellular gaps are seen between the axons. There is an increase in the cross sectional area of microtubules in 1-day old Df(3R)BSC499/Df(3R)MR22 mutant flies compared to controls, as well as a reduction in the density of microtubules per neurite.
FlyBase curator comment: In the Results section, 'Df(3R)MR22' is described as "a 62 kb deletion extending distally from EP(3)3203 that removes almost all of the tau locus". However, data in Figure 6A and the Methods section show that the deletion actually extends proximally from the insertion site, and that the deletion is approximately 72.5kb (on release 6 genome).