Figure 5.

Dβ2 coding segment deletion can occur via an intrachromosomal recombination reaction. (A) Diagram illustrating TCRβ locus structure of a heterozygous mutant in which a portion of the locus has been deleted by gene targeting resulting in the presence of only one copy of the Dβ2 gene segment. (B) Diagram showing a direct PCR strategy to detect perfect signal joints resulting from the deletion of Dβ2 gene segments. One of the PCR primers (horizontal arrows) overlaps the signal joint by several base pairs precluding the amplification of unrearranged gene segments. (C) Agarose gel analysis of PCR products obtained from the genomic DNA of several individual mice with either WT (Dβ2 +/+) or heterozygous Dβ2-deleted (Dβ2 +/KO) genotypes. The identities of PCR fragments were confirmed by DNA sequence analysis (Supplementary Table S3). Amplification of the β-globin locus serves as a DNA loading control. 63-12 is a RAG2-null cell line whose DNA served as a negative control.