Figure 2.

Analysis of TCRβ^M2 rearrangement in T cells. (A) TCRβ^M2 is similar to TCRβ^PF (Fig. 1A) except for mutation of the 3′ Dβ1 23-RSS heptamer (▴) as described in the text. The remaining 23-RSS (dotted ▵) and 12-RSSs (▵) are indicated. (B) BglII-digested genomic DNA isolated from kidney (K), thymocytes (T), ES cells transfected with TCRβ ^M2 (M2ES), or thymocytes isolated from mice containing TCRβ^M2 or TCRβ^PF miniloci was subjected to Southern blot analysis by using probe B. Shown are the expected size bands from the nonrearranged endogenous TCRβ locus (end), and the TCRβ^M2 and TCRβ^PF miniloci in the nonrearranged (GL), DJ, V(D)J/VJ, and VD rearrangement configurations. Also indicated (*) are the bands representing pseudonormal joins between tandemly integrated copies of the miniloci which have been described (15). The 9-, 6-, and 4-kb markers are shown. (C) PCR was carried out with primers PA and PB on thymocyte DNA from a wild-type (T), TCRβ^PF, and TCRβ^M2 mice. Indicated are the 1.2-, 0.7-, and 0.6-kb products expected for Vβ rearrangements to Dβ1, (D)Jβ1.1, and (D)Jβ1.2, respectively. The 1.5-, 1.0-, and 0.5-kb markers are shown.