Figure 4.

Elimination of Unfit Tissue Is Mediated by Comparison of Neuronal Fitness

(A–H) Cell death (TUNEL; white) in laterally injured right or uninjured left OLs 72 hr AD. Dashed arrows indicate the area of injury.

(B–H) Merged images with DAPI to visualize cell nuclei.

(I and J) Quantification of apoptotic cells 24 hr (I) and 72 hr (J) AD in injured right OLs and undamaged left OLs. Statistical significance is based on ANOVA. Genotypes were compared to UASlacz controls. ^∗∗∗p < 0.001. Bold lines show the median, and the boxed area represents 25% and 75% quantiles. Note the logarithmic scale. n, the number of OLs, is plotted below.

(K) Model for tissue replacement during adult brain regeneration in Drosophila. Direct fitness comparison of impaired neurons (red) after injury and newly generated and intact neurons (green) via Flower fitness fingerprints drives elimination of unfit neurons.

Scale bars represent 20 μm.