Selection of adoptively transferred TCR H-Y transgenic T cell precursor cells predominantly in female recipients. (A) 2 × 10⁵ B6 lin⁻ BM plus 0.5-1 × 10⁶ TCR H-Y transgenic DN2/3 T cell precursor cells were transplanted into male (left) and female (right) B6 recipients (n = 10). Constitutive and NFAT signal activity were determined. Thymi were harvested to determine the absolute thymocyte counts. (B) The mean of thymic NFAT activity from 5 identical experiments was quantified in male and female recipients. *P ≤ .05 was considered significant. (C) Dot plots display CD45⁺ extGLuc⁺ cells and percentage of DP, SP-CD4, and SP-CD8.