α₄β₇- and CD103-expressing subpopulations of IELps display distinct temporal patterns of development. Numerous thymocyte populations from RAG2p-GFP mice were analyzed for frequencies of GFP⁺ cells (top), and MFI of GFP expression within GFP⁺ cells (middle), to study the temporal dynamics of development from DP progenitors. GFP MFI within GFP⁺ cells were used to calculate the time elapsed from the DP stage to the time of interrogation using a GFP half-life of 54 h (bottom). (A) Analysis of conventionally selected lineages (CD4 and CD8) and agonist selected lineages (Treg, iNKT, and CD122^−/+ IELps). (B) Analysis of α₄β₇- and CD103-expressing subpopulations of CD122⁺ IELps. DP, CD4, CD8, Treg, iNKT, and IELp data were obtained over four individual experiments (n = 14). α₄β₇ and CD103 subpopulation data were obtained over two individual experiments (n = 7). (C) Normalized MFIs of S1P1 expression on the indicated thymocyte populations. S1P1 expression was normalized using control cells lacking primary antibody staining (normalized MFI = S1P1 MFI − control MFI). For DP, CD122⁻ IELps, and CD122⁺ IELps, data are compiled from seven mice over four individual experiments. For α₄β₇- and CD103-expressing subpopulations of CD122⁺ IELps, data are compiled from five mice over two independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (paired Student’s t test). Error bars indicate SEM.