(d) Percentage of mitochondria-containing Syto16low blood cells. Cells in peripheral blood from the indicated mice (10-20 weeks old) were stained with Syto16 and Mitotracker Deep Red. The population of mitochondriahigh cells among Syto16-negative cells was counted by FACS (mean±s.d., n=3). *P0.05 versus value of WT (ANOVA). 