ALLOZYME VARIATION IN NATURAL POPULATIONS

本建议中所述的工作旨在审查 多种主要组织相容性复合体（MHC）的遗传多态性 连锁和非连锁酶基因座。 本提案的目标是（1） 以确定与大鼠MHC相关的那些位点是否表现出 比其他基因编码的基因变异程度更高， 非MHC，连锁群，（2）确定是否存在 内基因座等位基因间的显著连锁不平衡 啮齿类动物和人类之间共有的同源染色体片段，以及（3） 检测和表征可能与大鼠相关的新酶变体 MHC（RT1复合物）作为标记基因用于本发明的遗传研究。 重要的复杂。 研究工作将系统地进行， 筛选血液和组织样本， 野生老鼠的种群。 每个基因座的多个位点在 大鼠种群和其他物种的可比研究。 新型别酶 变异体将被表征，并且它们的染色体连锁关系 只要有可能就建立。 本提案中概述的研究工作 解决了三个重要问题。 第一个问题是， 限制的多态性程度和连锁不平衡观察， 大鼠MHC是独特的或也见于不相关的连锁群。 的 这些实验的结果可能会对理论产生重大影响， 与高水平多态性的要求有关，以解释 MHC的功能。 第二，我们试图确定是否存在联系 不平衡可以被援引为一种机制来解释的保留， 同源染色体片段 保持大的，同源的 物种间的染色体片段是公认的，但它仍然 无论这些部分是偶然还是 主动选择 第三，发现了酶的新变体， 对MHC的作用可以在建立结构和基因方面发挥重要作用。 大鼠RT1复合物内基因座的顺序。

The work described in this proposal is designed to examine the degree of genetic polymorphism in a variety of major histocompatibility complex (MHC) linked and non-linked enzyme loci. The objectives of the proposal are (1) to establish whether or not those loci associated with the rat MHC exhibit a higher degree of genetic variation than those coded for by other, non-MHC, linkage groups, (2) to establish the presence or absence of significant linkage disequilibrium between alleles at loci within homologous chromosomal segments shared between rodents and man and, (3) to detect and characterize new enzyme variants potentially linked to the rat MHC (RT1 complex) for use as marker genes in genetic studies of this important complex. The research work will be conducted by systematically screening blood and tissue samples collected from widely-separate populations of wild rats. Multiple sites at each locus compared within the rat populations and to comparable studies in other species. New alloenzyme variants will be characterized and their chromosomal linkage relationships established whenever possible. The research work outlined in this proposal addresses three important problems. The first is whether or not the restricted degree of polymorphism and linkage disequilibrium observed in the rat MHC is unique or are also seen in unrelated linkage groups. The results of these experiments may have a substantial impact on theories that relate to the requirement for high levels of polymorphism to explain the function of the MHC. Secondly, we seek to determine if linkage disequilibrium can be invoked as a mechanism to explain the retension of homologous chromosomal segments. The retension of large, homologous chromosomal segments between species is well recognized but it remains to be established whether or not these segments are maintained by chance or by active selection. Third the discovery of new variants for enzymes linked to the MHC can be of important use in establishing the structure and gene order of loci within the RTl complex of the rat.