Sequence determination of a transcribed rabbit class II gene with homology to HLA-DQ alpha

The human HLA-DQ alpha probe was used to screen genomic and cDNA libraries constructed from a rabbit T-cell line. Clones containing highly homologous sequences were obtained from both libraries and their sequences were determined. The organization of the RLA-DQ gene was determined by comparison of the nucleotide sequences of the genomic clone to that of the corresponding cDNA clone. This analysis allowed assignment of the complete structure of the RLA-DQ alpha chain. Comparisons with human and mouse class II products revealed that RLA-DQ is more closely related to HLA-DQ/DX than to H-2A. In contrast to the DQ/DX region of man, which contains at least two distinct alpha genes, the rabbit genome contains a single DQ gene which is equally distant from the HLA-DQ or -DX genes. The rabbit DQ alpha gene, like human HLA-DQ, is transcribed in T cells.