Variable region (V delta) gene segment most frequently utilized in adult thymocytes is 3' of the constant (C delta) region.

Abstract
A variable region (V.delta.5) of the T-cell receptor (TcR) .delta. chain that is preferentially expressed in adult murine thymocytes is located 2.5 kilobase 3'' of the constant region (C.delta.) element. The V.delta.5 coding sequence is in a transcriptional orientation opposite the J.delta. (joining region) and C.delta. coding elements and rearranges by inversion. The C.delta. is divided into four exons, three of which encode amino acids of TcR .delta. polypeptide, and the fourth comprises the entire 3'' untranslated region. In this respect, C.delta. resembles C.alpha. rather than C.beta. or C.gamma.