The rearrangement and expression of six different mouse T-cell receptor TCRDV (VS) gene subfamilies have been studied in BALB/c mouse spleen. The results show that all the TCRDV gene segments studied can be rearranged and expressed with both the TCRA (c~) and the TCRD (6) chain. The apparently restricted and separated V gene repertoire for the TCRD and TCRAT-cell receptor may result from thymus and peripheral selection rather than from selective rearrangement in the DNA level. Several J gene segments show much higher concentration in spleen with TCRDV gene segments, however, these J gene segments do not tend to be located at either end of the J gene cluster. kllrafluelilm Lymphocytes are an important functional part of the immune system and are divided into two major cell types. B cells synthesize and release immunoglobulins (Ig), and T cells assemble and display T-cell antigen receptor (TCR) on its cell surface. The TCR polypeptides are encoded by the TCRA, TCRB, TCRG and TCRD gene families. The predominant circulating T cells are those cells bearing TCRA/TCRB (~/[3) TCR, while the TCRG/'TCRD (7/8)expressing T cells are present as a minor population. However, in certain epithelia locations subsets of y/8 T cells locate exclusively or preferentially and become the predominant form of lymphocyte (reviewed in Raulet 1989; Havran and Allison 1991). The TCR polypeptides, like the