Selective developmental defect in NK cells of the Id2−/−
fetal thymus. (A) Cells of 17-dpc FT were stained with
CD3-, NK1.1-, CD4-, and CD8-specific mAbs. Total thymocyte numbers were
1.5 ± 0.9 × 106, 1.8 ± 0.6 ×
106 and 0.7 ± 0.6 × 106 for
Id2+/+, Id2+/−, and Id2−/− FT,
respectively. (B) Cells of 14-dpc FT were stained with
FITC-conjugated mAbs specific for TER119, Mac-1, Gr-1, B220, NK1.1,
CD3, CD4, and CD8. Only FL-1-negative cells were analyzed for
expression of CD44 vs. CD122 and CD44 vs. CD25. Total thymocyte numbers
were 5.6 ± 1.4 × 104, 3.2 ± 1.4 ×
104, and 1.5 ± 1.3 × 104 for
Id2+/+, Id2+/−, and Id2−/− FT,
respectively. Numbers represent the percentage of cells in the gated
population and in each quadrant in A and
B.