Satz M L, Wang L C, Singer D S, Rudikoff S
J Immunol. 1985 Sep;135(3):2167-75.
Two nonallelic porcine class I MHC (SLA) genes have been isolated and characterized. Both genes are expressed in mouse L cells, directing the synthesis of class I SLA molecules that carry common monomorphic determinants but are serologically distinct. The corresponding DNA sequences have been determined. The organization of both of these genes is similar to that of other class I genes: a leader exon, three exons encoding extracellular domains, a transmembrane exon, and three intracytoplasmic exons. The two genes are highly homologous in both exon and intron segments, with average homologies of 88% and 80%, respectively. Nucleotide changes in exon 2 are clustered, whereas those in the other exons are dispersed throughout. Comparison of the swine DNA sequences with class I genes from other species reveals a generally high conservation of exons 2, 3, 4, and 6 with lower homology in the remaining protein-encoding domains. Introns are markedly less well conserved, although moderate homology is found between swine and human class I MHC genes in both introns and 3' flanking regions. Taken together with comparisons of the deduced protein sequences, these data indicate an order of swine greater than human greater than rabbit greater than mouse in the relationship of class I genes.
两个非等位猪I类主要组织相容性复合体（SLA）基因已被分离和鉴定。这两个基因均在小鼠L细胞中表达，指导合成携带共同单态决定簇但血清学上不同的I类SLA分子。相应的DNA序列已被测定。这两个基因的结构与其他I类基因相似：一个前导外显子、三个编码细胞外结构域的外显子、一个跨膜外显子和三个胞质内外显子。这两个基因在外显子和内含子片段中高度同源，平均同源性分别为88%和80%。外显子2中的核苷酸变化成簇，而其他外显子中的变化则分散分布。将猪的DNA序列与其他物种的I类基因进行比较，发现外显子2、3、4和6通常具有高度保守性，而其余蛋白质编码结构域的同源性较低。内含子的保守性明显较差，尽管在猪和人类I类主要组织相容性复合体基因的内含子和3'侧翼区域中发现了适度的同源性。结合推导的蛋白质序列比较，这些数据表明在I类基因的关系中，猪大于人类大于兔子大于小鼠。
