FIG. 4.

Endogenous TCRβ expression in TCRβ-SCID mice. Thymus RNA from individual 2-week-old untreated or irradiated TCRβ-SCID mice was reverse transcribed into cDNA. RT-PCR was performed using eight different Vβ-specific sense primers coupled with a TCR-Cβ anti-sense primer. The products were Southern blotted and hybridized with a TCR-Cβ probe. Note that, as expected, Vβ8 transcripts were detectable in all thymus samples from SCID mice expressing the Vβ8.2 transgene. Thymocyte RNA obtained from 4- to 6-week-old nontransgenic SCID and BALB/c mice were included as negative and positive controls, respectively, for the presence of TCRβ transcripts.