Allotypes of the constant region of the rabbit T cell receptor beta-2 chain.
Our laboratory previously reported that there was restriction fragment length polymorphism of TCR C beta genes in rabbits. EcoRI digests of DNA from different rabbits gave fragments of 9 and 6 kb (C beta a) or 14 and 6 kb (C beta b) that hybridized to a C beta cDNA probe. We also reported that the 9- and 14-kb types segregated as Mendelian traits and that there were allotypic differences in the first exon of the C beta 1 genes of C beta a and C beta b animals. Here we report the DNA sequence of the C beta 2 gene present in the 6-kb EcoRI fragment from a C beta b animal and compare the exon sequences with that of a cDNA from a C beta a animal. We find replacement changes in the first and third exons that probably represent allotypic forms of the rabbit C beta 2 gene. The genomic DNA 5' of exon 1 of both beta 1 and beta 2 contain alternating purine/pyrimidine repeat sequences. The genomic C beta 2 has an open reading frame of 69 amino acids in frame with exon 1 similar to a longer one previously found 5' of exon 1 of C beta 1. Further 5' of this region, rabbit C beta 1 and C beta 2 DNA sequences are only about 66% similar. Both the C beta 1 and C beta 2 sequences have two chi sequences; one in exon 1 with a perfect match and one in the intron downstream of exon 1 with one mismatch. Alternating purine/pyrimidine repeats and chi sequences found in rabbit C beta 1 and C beta 2 genes may have contributed to process(es) of gene duplication and/or conversion.
Harindranath
N
N
Molecular Immunogenetics Section, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892.
Lamoyi
E
E
Mage
R G
RG
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000302:isolation & purification; D005796:Genes; D005803:Genes, Immunoglobulin; D006801:Humans; D007126:Immunoglobulin Allotypes / Q000235:genetics* / Q000302:isolation & purification; D007127:Immunoglobulin Constant Regions / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008969:Molecular Sequence Data; D011817:Rabbits / Q000235:genetics*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000302:isolation & purification; D016693:Receptors, Antigen, T-Cell, alpha-beta; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000378:metabolism*
D007126:Immunoglobulin Allotypes; D007127:Immunoglobulin Constant Regions; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D004247:DNA