This transgene uses a genomic immunoglobulin kappa (Ig) chain promoter to drive expression of rearranged V and J segments from the KL25 clone, including leader and intronfollowed by a light chain kappa constant domain, and IRES followed by a cell surface reporter protein consisting of the murine Thy1.1 ectodomain fused to the transmembrane and cytoplasmic domains of the mouse PDGF receptor. (J:259174)