(a) Three-colour flow cytometry of erythroid cells from WT embryonic liver (E14.5) stained with anti-Ter119, anti-CD71 and Mitotracker Deep Red. (Left upper panel) Ter119 versus CD71 fluorescence. (Other panels) FSC versus Mitotracker fluorescence of the R1 (right upper panel), R2 (left lower panel) and R3 (right lower panel) fractions. (b,c) Percentage of cells with a low number of mitochondria (mitochondrialow cells) among CD71−Ter119+ EC. Erythroid cells from the liver (E14.5 and E18.5) and peripheral blood (E18.5) of indicated mice were stained with anti-Ter119, anti-CD71 and Mitotracker Deep Red. 