【摘要】 本研究从长穗偃麦草与老芒麦中分离了63个α-醇溶蛋白基因的开放阅读框,并进行了序列分析,结果表明90%的基因中含有提前终止密码子或移码突变。与已经发表的α-醇溶蛋白基因序列比对发现,这些基因都编码相似的信号肽、重复区和C-末端,但在两个多聚谷氨酰氨区差异明显。依据重复区中前三个氨基酸序列分析,出现了GRV和RV两种新的亚基类型;在第一个多聚谷氨酰氨区出现了(Q)3AR(Q)5、(Q)2AR(Q)5、(Q)3A新类型。乳糜泻抗原分析显示,来自老芒麦的一个真基因EU016530中含有两种乳糜泻抗原(glia-α2和glia-α),而来自长穗偃麦草的真基因中没有发现乳糜泻抗原的存在,仅有假基因EU018257含有乳糜泻抗原glia-α。进化分析表明,二倍体长穗偃麦草α-醇溶蛋白基因与十倍体的长穗偃麦草α-醇溶蛋白基因有较近的亲缘关系;而老芒麦的α-醇溶蛋白基因与其它小麦族的基因聚在一起。更多还原

【Abstract】 Sixty-three α-gliadin open reading frames(ORF) were characterized from diploid Lophopyrum elongatum and tetroploid Elymus sibiricus.Sequence comparison revealed that about 90% of them contained an internal stop codon or frameshift.Alignment between these ORFs and reported α-gliadin sequences reveal that they coded identical signal peptide domain,repetitive domain and C-terminal region,except polyglumatine domains.Analysis of the first three codons in repetitive domains reveals two new types of motifs(GRV and RV).Novel types of motifs,including(Q)3AR(Q)5,(Q)2AR(Q)5,(Q)3A,were characterized in the first polyglumatine region.Three known types of celiac disease(CD) epitopes in Triticum were screened and compared in the repetitive and the C-terminal unique domains.A potential real gene(EU016530) from E.sibiricus contained two types of CD epitode(glia-α2 and glia-α),whereas,the real genes from diploid L.elongatum are found to contain no CD epitode,only with pseudogenes EU018257 containing glia-α.Phylogenetic analysis showed that α-gliadins from diploid L.elongatum were closely related to those from decaploid L.elongatum,while that from E.sibiricus were more homologous with those from other Triticum species.更多还原