T-cell receptor genes (TCR) are split into variable (V), diversity (D), joining (J) and constant (C) regions in the germline DNA. During the development of T-cells, these gene segments are rearranged to generate a VDJ-C configuration. It is then transcribed into a precursor mRNA. Like many other eukaryotic pre-mRNAs, the TCR mRNA precursor is spliced to produce a functional polypeptide. Analyses of the splice sites of TCR-α, TCR-β, and TCR-γ genes show that they share striking homologous sequences at both the 5` polypyrimidine stretches and 3` splice sites. Moreover, base pairing between the 5` splice site and U₁, snRNA is evident. However, the U₂-binding site and U_5-binding site have not been found.