title: Variations and classification of toxic epitopes related to celiac disease among α-gliadin genes from four Aegilops genomes.
abstract: The α-gliadins are associated with human celiac disease. A total of 23 noninterrupted full open reading frame α-gliadin genes and 19 pseudogenes were cloned and sequenced from C, M, N, and U genomes of four diploid  Aegilops  species. Sequence comparison of α-gliadin genes from Aegilops and  Triticum  species demonstrated an existence of extensive allelic variations in Gli-2 loci of the four Aegilops genomes. Specific structural features were found including the compositions and variations of two polyglutamine domains (QI and QII) and four T cell stimulatory toxic epitopes. The mean numbers of glutamine residues in the QI domain in C and N genomes and the QII domain in C, N, and U genomes were much higher than those in Triticum genomes, and the QI domain in C and N genomes and the QII domain in C, M, N, and U genomes displayed greater length variations. Interestingly, the types and numbers of four T cell stimulatory toxic epitopes in α-gliadins from the four Aegilops genomes were significantly less than those from Triticum A, B, D, and their progenitor genomes. Relationships between the structural variations of the two polyglutamine domains and the distributions of four T cell stimulatory toxic epitopes were found, resulting in the α-gliadin genes from the Aegilops and Triticum genomes to be classified into three groups.
authors: College of Life Science, Capital Normal University, 100048 Beijing, China.
authors: Jie
authors: J
authors: Li
authors: Shunli
authors: S
authors: Wang
authors: Shanshan
authors: S
authors: Li
authors: Pei
authors: P
authors: Ge
authors: Xiaohui
authors: X
authors: Li
authors: Wujun
authors: W
authors: Ma
authors: F J
authors: FJ
authors: Zeller
authors: Sai L K
authors: SL
authors: Hsam
authors: Yueming
authors: Y
authors: Yan
mesh_terms: D000483:Alleles; D002446:Celiac Disease / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D018744:DNA, Plant / Q000737:chemistry / Q000378:metabolism; D004171:Diploidy; D000939:Epitopes / Q000235:genetics*; D014644:Genetic Variation / Q000276:immunology; D018745:Genome, Plant; D005903:Gliadin / Q000235:genetics*; D006109:Poaceae / Q000145:classification / Q000235:genetics*; D013045:Species Specificity; D014908:Triticum / Q000235:genetics / Q000378:metabolism
chemical_list: D018744:DNA, Plant; D000939:Epitopes; D005903:Gliadin