Mapping of Mhc class I and class II regions to different linkage groups in the zebrafish, Danio rerio
Mapping of Mhc class I and class II regions to different linkage groups in the zebrafish, Danio rerio
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DOI：
10.1007/s002510050251
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发表时间：
1997-01-01
期刊：
影响因子：
3.2
通讯作者：
Klein, J
中科院分区：
文献类型：
--
作者：
BingulacPopovic, J;Figueroa, F;Klein, J
哺乳动物主要组织相容性复合体（Mhc）由三个紧密相连的区域组成，I， II和III，占据单个染色体片段。I区的I类位点和II区的II类位点在结构、功能和进化上具有相关性。III区插入在I区和II区之间，包含与I类和II类位点无关的位点，并且彼此不相关。有迹象表明，鸟类和两栖动物中也存在类似的Mhc组织。在这里，我们证明了在硬骨鱼的代表斑马鱼（Danio rerio）中，II类基因座被分为两个连锁群，这两个连锁群与包含I类基因座的连锁群不同。β(2)-微球蛋白编码基因松散地连接到II类位点之一。编码补体因子B的基因是哺乳动物的III区基因之一，在斑马鱼中既不与I类位点相连，也不与II类位点相连。这些结果，结合初步数据表明，另一目硬骨鱼的I类和II类区域也在不同的连锁群中，表明这两个区域的紧密连锁对于I类和II类位点的表达调节或共同进化都不是必需的。他们还提出了一个问题，即四足动物中I类和II类位点的连锁是原始的还是衍生的特征。
The mammalian major histocompatibility complex (Mhc) consists of three closely linked regions, I, II, and III, occupying a single chromosomal segment. The class I loci in region I and the class II loci in region II are related in their structure, function, and evolution. Region III, which is intercalated between regions I and II, contains loci unrelated to the class I and II loci, and to one another. There are indications that a similar Mhc organization exists in birds and amphibians. Here, we demonstrate that in the zebrafish (Danio rerio), a representative of the teleost fishes, the class II loci are divided between two linkage groups which are distinct from the linkage group containing the class I loci. The beta(2)-microglobulin-encoding gene is loosely Inked to one of the class II loci. The gene coding for complement factor B, which is one of the region III genes in mammals, is linked neither to the class I nor to the class II loci in the zebrafish. These results, combined with preliminary data suggesting that the class I and class II regions in another order of teleost fish are also in different linkage groups, indicate that close linkage of the two regions is not necessary either for regulation of expression or for coevolution of the class I and class II loci. They also raise the question of whether linkage of the class I and class II loci in tetrapods is a primitive or derived character.