The major histocompatibility class I locus in Atlantic salmon (Salmo salar L.):: polymorphism, linkage analysis and protein modelling
The major histocompatibility class I locus in Atlantic salmon (Salmo salar L.):: polymorphism, linkage analysis and protein modelling
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DOI：
10.1007/s00251-002-0499-8
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发表时间：
2002-11-01
期刊：
影响因子：
3.2
通讯作者：
Stet, RJM
中科院分区：
文献类型：
--
作者：
Grimholt, U;Drablos, F;Stet, RJM
以大西洋鲑Mhc I类基因保守外显子4为探针，构建了大西洋鲑Mhc I类基因cDNA文库，为研究大西洋鲑Mhc I类基因在繁殖群体中的多态性奠定了基础。12个不同的等位基因被确定在82个母畜和公畜研究。没有个体表达超过两个等位基因，这对应于位于3 '-非翻译尾内的多态性标记的二倍体分离模式。Sasa-UBA和Sasa-TAP 2B基因座之间的紧密连锁加强了Sasa-UBA是大西洋鲑鱼中主要的MHC I类基因座的主张。我们没有发现证据表明，第二个表达的经典或非经典MHC I类基因座在大西洋鲑鱼。鲑鱼类MHC I类序列的系统发育分析显示虹鳟鱼，褐鳟鱼和大西洋鲑鱼之间的保守域。鉴定了α（1）结构域改组的证据，并且可以定义通过胞质尾基因片段的剩余α（2）的谱系。发现一个等位基因的编码序列与两个不同的标记相关，表明在3 '-尾二核苷酸重复序列本身内发生重组。几个Sasa-UBA等位基因的蛋白质建模显示其肽结合结构域的明显差异，并使进一步了解高多态性的功能。
A cDNA library screening using the conserved exon 4 of Atlantic salmon Mhc class I as probe provided the basis for a study on Mhc class I polymorphism in a breeding population. Twelve different alleles were identified in the 82 dams and sires studied. No individual expressed more than two alleles, which corresponded to the diploid segregation patterns of the polymorphic marker residing within the 3'-untransiated tail. Close linkage between the Sasa-UBA and Sasa-TAP2B loci strengthens the claim that Sasa-UBA is the major Mhc class I locus in Atlantic salmon. We found no evidence for a second expressed classical or non-classical Mhc class I locus in Atlantic salmon. A phylogenetic analysis of salmonid Mhc class I sequences showed domains conserved between rainbow trout, brown trout and Atlantic salmon. Evidence for shuffling of the alpha(1) domain was identified and lineages of the remaining alpha(2) through the cytoplasmic tail gene segment can be defined. The coding sequence of one allele was found associated with two different markers, suggesting recombination within the 3'-tail dinucleotide repeat itself. Protein modelling of several Sasa-UBA alleles shows distinct differences in their peptide binding domains and enables a further understanding of the functionality of the high polymorphism.