GFP expression profiles in MommeD7-D10. Erythrocytes from 3-week-old mice were analyzed by flow cytometry. In each case, the expression profiles from one litter of a heterozygous intercross are displayed. The phenotypically wild-type mice are shown in black, heterozygotes in dark grey, and homozygotes (MommeD8 and D10 only) in light grey. The x-axis represents the erythrocyte fluorescence on a logarithmic scale, and the y-axis is the number of cells detected at each fluorescence level. For quantitative and statistical significance, see Table 1.