Figure 4

Figure 4

The V(D)J recombination of Rag2^KI/KI mice is severely impaired. Flow cytometric analysis of T and B cell development in Rag2^+/+, Rag2^+/KI and Rag2^KI/KI mice. (A,B) TCRβ rearrangement was found to be decreased via semiquantitative PCR, which was used to detect D_β-J_β rearrangement in DN3 thymocytes (CD4⁻CD8⁻CD44⁻CD25⁺ population) sorted from Rag2^KI/KI mice, their WT littermates and RAG2^−/− mice. Input control: CD14 (bottom). PCR amplification was performed with fivefold serial dilutions of genomic DNA. The results are representative of three independent experiments. (C) The intracellular TCRβ expression level in Rag2^KI/KI mice was largely diminished compared to that in Rag2^+/+ or Rag2^KI/+ mice. The TCRβ expression level was measured by flow cytometry. (D–G) The surface expression of CD4, CD8, B220, IgM, and CD43 in Rag2^KI/KI mice (mice with two zRAG2 knock-in alleles) and Rag2^+/+ mice (WT littermates) was analyzed by flow cytometry. (D) CD44 and CD25 surface expression in DN cells of the thymus. (E) CD4 and CD8 surface expression on thymocytes. (F) IgM⁻ bone marrow cells were analyzed for surface expression of B220 and CD43. (G) The B220 and IgM surface expression on bone marrow cells. The results are representative of three independent experiments.