A transgenic TCRβ chain partially corrects the effects of ADA inhibition. FTOCs were performed at day 14 of gestation with or without 5 μM dCF with thymuses from control littermates (a and b) and TCRβ chain transgenic mice (c and d). After 2 days, thymocytes were harvested, counted, and stained with FITC-anti-CD4, PE-anti-CD8, and PI to exclude dead cells. (e) The degree of rescue of thymocyte differentiation (mean ± SD) is shown as a function of the length of the culture period. The “% rescue” is defined as (number of DP thymocytes per lobe from dCF-treated transgenic cultures)/(number of DP thymocytes per lobe from control transgenic cultures) × 100. The number of experiments for each time point is shown beneath each bar.