Absence of Thy-1 antigen in L-cell X mouse lymphoma hybrids

Hybrid clones arising after inactivated Sendai virus mediated cell fusion between a bromodeoxyuridine-resistant derivative of the BALB/c mouse lymphoma cell line, S49, and a thioguanine-resistant derivative (A9) of the C3H mouse fibroblast cell line, L929, were selected in HAT medium. The responses of the clones to growth inhibitors as well as their chromosome numbers were consistent with properties expected of hybrids. Hybrid clones expressed the major histocompatibility (H-2) surface antigens of both parental types, i.e., H-2d of BALB/c and H-2k of C3H. The Thy-1.2 antigen, expressed on the surface of the lymphoma parent but not the fibroblast parent, was not detected on the hybrids.