Isolation of T cell receptor gamma/delta chain constant genes from minke whale

The polymerase chain reaction using oligonucleotides based on consensus sequences from other species allowed us to amplify minke whale (Balaenoptera acutorostrata) T cell receptor (TcR) gamma and delta constant genes. Two types of Cgamma clones were obtained which only differ by one mismatch. These minke whale Cgamma clones showed 83% nucleotide and 70% amino acid sequence similarity to the corresponding region of the human TRGC genes. The minke whale Cdelta sequences were all identical, and showed 86% nucleotide and 77.8% amino acid sequence similarity to the human TRDC gene. The whale Cgamma and Cdelta clones were used as probes for Southern blot analysis. The data confirmed that there is a unique Cdelta gene in minke whale. Two different Cgamma genes were detected, one of them also cross-hybridizing with a human Cgamma probe, suggesting that the Cgamma locus in minke whale consists of at least two different constant genes.