In the human T-cell rearranging gamma (TRGγ) locus, five joining (J) segments have been identified: J1, J2 and three additional segments JP, JP1 and JP2. We report the sequence of the germline JP1 segment and compare it with the other human and mouse Jγ segments. We also demonstrate that rearrangements to the three additional Jγ segments can be identified by hybridization of the KpnI digests to the Jγ1 probe pH60. Since rearrangements to J1 or J2 can be assigned, using the same pH60 probe, to one of the nine variable (V) γ genes known to rearrange [(1987) EMBO J. 6, 1945–1950], our results show that a unique probe can detect all the TRGγ rearrangements and be particularly useful for assessing the preferential usage of Vγ and Jγ segments in the TRG γ-expressing cells.
