Pre-TCR-like signals induce differentiation of Lck-Cre-Mycfl/fl-Rag2-/- thymocytes. (A) FACS profiles for CD4/CD8 (top panels) and lin-/CD44/CD25 expression 4 days after injection (intraperitoneally) of 50 μg α-CD3 mAb. Numbers given indicate the percentages of cells in the respective quadrants. FACS plots are representative of observations obtained in at least 3 independent experiments. (B) Cellularity was calculated from total thymocyte numbers and the fraction of the indicated subsets. Error bars indicate SD. Eleven LckCre-Mycfl/fl-Rag2-/- and 6 LckCre-Rag2-/- were analyzed to obtain statistics. (C) Semiquantitative PCR with 5-fold serial dilutions was performed to detect the floxed Myc allele. Genomic DNA was obtained from FACS-sorted DN3, DN4, and DP cells. (D) Cell size of DN4 stage thymocytes. FSC as observed by FACS.
