Tpre, a new alloantigen encoded in the IgT-C region of chromosome 12, is expressed on bone marrow of nude mice, fetal T cell hybrids, and fetal thymus.

A new T cell alloantigen, Tpre, has been identified by monoclonal F.6.9.1 antibody. This antigen is encoded by a gene linked to the cluster of T cell antigens in the IgT-C region of chromosome 12 (Tthy, Tind, and Tsu). Tpre is distinct from Tthy, Tind, or Tsu because it is expressed on bone marrow cells of the AKR nustr/nustr, the thymus repopulating precursor cell in normal adult marrow, and normal fetal thymocytes. Several fetal and adult T cell hybrids express these antigens independently. Tpre and Tthy are expressed on largely overlapping cell populations in adult thymus.