The human T-cell receptor gamma (TRG) genes.
Lefranc MP., Rabbitts TH.
The human T-cell receptor gamma (TRG) chain genes, like those encoding the T-cell receptor alpha- and beta-polypeptides, undergo rearrangements specifically in T cells. The human TRG locus, which has been completely mapped, is composed of two constant region genes (TRGC), five joining segments (TRGJ) and at least 14 variable gamma-genes (TRGV). Eight variable genes are functional and belong to four different subgroups. The product of the rearranged TRG gene is the gamma-chain which is expressed, along with the delta-chain, at the surface of a subset of T lymphocytes. Although some gamma delta + cells display a cytolytic activity, their precise function remains to be elucidated.