cDNA cloning and genomic structure of the duck (Anas platyrhynchos) MHC class I gene.
In order to provide data for studies on disease resistance, duck MHC class I cDNA (Anpl-MHC I) was cloned from a duck cDNA library and the genome structure was investigated. Anpl-MHC I genes encoded 344-355 amino acids. The genomic organization is composed of eight exons and seven introns. Based on the genetic distance, Anpl-MHC I cDNA from six individuals can be classified into four lineages (from Anpl-UAA to Anpl-UDA). A total of 28 amino acid positions in the peptide-binding domain (PBD) showed high scores by Wu-kabat index analysis. The Anpl-MHC amino acid sequence displayed seven critical HLA-A2amino acids that bind with antigen polypeptides, and have an 83.6-88.5% amino acid homology with each lineage, a 55.2-64.6% amino-acid homology with chicken MHC class I (B-FIV21, B-FIV2, Rfp-Y), and a 40.3-42.8% homology with mammalian MHC class I. Nested PCR detected that Anpl-MHC I can be expressed in the brain, heart, kidney, intestines and bursa. Compared with the human HLA-A2 tertiary structure of the PBD, Anpl-MHC I had an insertion or deletion variation in four domains (A-D). The phlyogenetic tree appears to branch in an order consistent with accepted evolutionary pathways.
Xia
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The Key Laboratory of Veterinary Molecular Biology, College of Veterinary Medicine, China Agricultural University, 100094 Beijing, PR China. xiachun@cau.edu.cn
Lin
C Y
CY
Xu
G X
GX
Hu
T J
TJ
Yang
T Y
TY
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D004372:Ducks / Q000235:genetics* / Q000378:metabolism; D005091:Exons / Q000235:genetics*; D015723:Gene Library; D005805:Genes, MHC Class I / Q000502:physiology*; D007438:Introns / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary