Microglia are unable to effectively clear endogenous debris in clcn7 mutants. (A) TUNEL assay revealing a significantly greater intensity of apoptotic punctae inside the microglia of clcn7 mutants (n=6, mean=73.3, s.d.=39.2, s.e.m.=4.5) than in clcn7 heterozygotes (n=12, mean=35.5, s.d.=22.2, s.e.m.=1.8). (B) Microglia in clcn7 mutants show an accumulation of NBT:DsRed neuronal punctae. (C) The intensity of DsRed punctae inside microglia was significantly greater in clcn7 mutants (n=13, mean=118, s.d.=42.4, s.e.m.=5.7) relative to clcn7 heterozygotes (n=29, mean=43.2, s.d.=33.4, s.e.m.=2.9). (D) High magnification image showing accumulation of neuronal debris inside microglia. (E) Low magnification image showing accumulation of NBT:DsRed punctae in the midbrain, where microglia are enriched. Images are representative of at least three independent experiments. Two-tailed unpaired t-test with Welch's correction was performed to calculate the significance in all graphs; graphs show mean±s.d. Scale bars: 50 µm. A.U., arbitrary units.
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