FIGURE 3. Immunoglobulin gene rearrangements in thymocytes of reconstituted Rag2^–/– mice.

PCR detection of immunoglobulin gene rearrangements in Ly5.2⁺CD4⁺CD8⁺ (double-positive) thymocytes, which were sorted 8–12 weeks after transplantation of Rag2^–/– Ly5.1⁺ recipient mice with in vitro Pax5-deleted mature B cells (a) or in vivo Pax5-deleted mature B cells (b). Oligoclonal Vh–DJh, V–J and V1–J rearrangements were detected in Ly5.2⁺ double-positive thymocytes in addition to polyclonal V14–J2 rearrangements. B220⁺ splenocytes (B) and double-positive thymocytes (T) from Pax5^fl/fl mice were used as controls. Numbers indicate rearrangements involving different J2, Jh or J segments. PCR genotyping revealed full conversion of the fl to the Pax5 allele in all Ly5.2⁺ thymocytes. The Pax5 mutant (–) germline allele is indicated. The VhGam3.8, VhQ52 and Vh7183 genes are also known as Igh-VGAM3.8, Igh-VQ52 and Igh-V7183, respectively.