Characterization of a C alpha gene of swine.
The cDNA sequence encoding the constant region of the porcine IgA heavy chain as well as the exon-intron structure of the germline gene, have been determined. A cDNA clone (1A1) spanning the CH3 domain and part of the CH2 domain was isolated from a porcine mesenteric lymph node cDNA library. Clone 1A1 was aligned with a PCR-generated DNA fragment encompassing the CH1 domain through the 5' end of the CH3 domain to derive the complete cDNA sequence. Comparison with other mammalian C alpha heavy chains (hinge regions excluded) indicated that the deduced amino acid sequence of porcine C alpha is most homologous with the human C alpha subclasses (> 70%), followed by mouse C alpha (61%) and a consensus sequence of the 13 rabbit C alpha heavy chains (59%). The greatest sequence homology was found among the CH3 domains in all species. A striking feature of porcine C alpha is its short six amino acid hinge which like other mammalian IgAs, is encoded with the CH2 domain. Sequence analysis of germline C alpha, generated by PCR from liver or sperm DNA, revealed an exon-intron organization similar to other mammalian C alpha genes. Genomic Southern blot data are consistent with the presence of a single C alpha gene within the porcine genome. Data obtained in these studies will be valuable in pursuing the use of swine as a model in immunological research.
Brown
W R
WR
Department of Microbiology, University of Iowa Medical School, Iowa City 52242.
Butler
J E
JE
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D018076:DNA, Complementary; D005803:Genes, Immunoglobulin; D006801:Humans; D007070:Immunoglobulin A / Q000235:genetics*; D007137:Immunoglobulin alpha-Chains / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D013552:Swine / Q000235:genetics* / Q000276:immunology*
D018076:DNA, Complementary; D007070:Immunoglobulin A; D007137:Immunoglobulin alpha-Chains