Fig. 2. Notch receptor ligation generates T cells from P-Sp/AGM, but not from YS of early embryos. (A) YS and P-Sp from E9.0-9.5 embryos (somites 15-20) were dissected and cultured on OP9 cells for 14 days without exogenous cytokines. The cultures were then stained for lymphocyte markers including TCRß and TCR. (B) E9.0-9.5 P-Sp were cultured on OP9-DL1 with or without additional cytokines for 14 days in parallel, the cultures were then stained for TCR and TCRß from comparison. (C) E9.0-9.5 P-Sp were cultured on OP9-DL1 with (black bars) or without additional cytokines (white bars) for 14 days in parallel. The total cell number per tissue (left) and T cells produced (right) are shown.