FIG. 5.

Southern blot detection of TCRδ coding end breaks and rearrangements in TCRβ-SCID thymocytes. (A) Genomic DNA was extracted from thymocyte cell suspensions prepared from 4 individual 6-week-old TCRβ-SCID mice and a nontransgenic littermate, as well as from the thymus and kidney of a 4-week-old wild-type C57BL/6 animal. The DNA was digested with EcoRI, electrophoresed, and Southern blotted. The membrane was hybridized with probe no. 4, which detects a single germline fragment between Jδ1 and Jδ2 and allows detection of rearrangement to Jδ1 (82). The positions of germline fragments, Dδ2 coding end breaks (CE), DJδ or D-DJδ partial rearrangements, and complete V-D-Jδ rearrangements are indicated. Molecular size standards are included in the far right lane, with sizes in kilobases. (B) Partial TCRδ locus map. The position of probe no. 4 within the TCRδ locus is displayed (adapted from reference 82). EcoRI sites are indicated, as are the CE breaks and germline fragment detected in this assay.