Linkage disequilibrium and evolutionary relationships of DNA variants (restriction enzyme fragment length polymorphisms) at the serum albumin locus.
Linkage disequilibrium and evolutionary relationships of DNA variants (restriction enzyme fragment length polymorphisms) at the serum albumin locus.
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血清白蛋白位点 DNA 变异（限制性酶片段长度多态性）的连锁不平衡和进化关系。
DOI：
10.1073/pnas.81.11.3486
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发表时间：
1984
影响因子：
11.1
通讯作者：
Motulsky,AG
中科院分区：
文献类型：
--
作者：
Murray,JC;Mills,KA;Demopulos,CM;Hornung,S;Motulsky,AG
已鉴定出4种额外的DNA变体（限制性内切酶片段长度多态性），使人血白蛋白基因座上共有8个多态性位点。这8个位点是用27种不同的限制性内切酶用白蛋白cDNA探针从20，000个核苷酸中筛选出689个后发现的。因此，85个核苷酸中有一个可能是多态性的。计算任意两个随机选择的染色体之间的平均核苷酸多样性为1/500。我们观察到显着的连锁不平衡之间的八个变种。在白种人、黑人和亚洲人的160条染色体上，在256种可能的组合中仅观察到7种单倍型。在所有三个人类种族中发现了两种单倍型，表明它们的起源早于人类种族分歧。三种最罕见的单倍型似乎代表更常见的单倍型之间的重组事件。所有交叉都发生在同一个区域。对几种非人类灵长类动物的研究表明，一种单倍型的起源早于人类与非洲猿的分歧。虽然这是不可能排除这种紧密连锁的选择或固定的维护，它建议，在染色体位点的白蛋白基因的着丝粒附近的4号染色体的单倍型的数量有限，可能是重组减少的结果。
Four additional DNA variants (restriction enzyme fragment length polymorphisms) making a total of eight polymorphic sites at the human albumin locus have been identified. These eight sites were found after screening 689 of 20,000 nucleotides by using cDNA probes for albumin with 27 different restriction enzymes. One in 85 nucleotides was therefore potentially polymorphic. The average nucleotide diversity between any two randomly chosen chromosomes was calculated to be 1/500. We observed marked linkage disequilibrium between the eight variants. Only 7 haplotypes among 256 possible combinations were observed in 160 chromosomes from Caucasoids, Blacks, and Asians. Two haplotypes were found in all three human races, indicating that their origin predated human racial divergence. The three rarest haplotypes appear to represent recombinational events between the more common haplotypes. All crossovers occurred in the same general region. Studies of several nonhuman primates indicated that the origin of one haplotype predated the human-African ape divergence. Although it is not possible to rule out maintenance of this tight linkage by selection or fixation, it is suggested that the limited number of haplotypes at the chromosomal site of the albumin gene near the centromere of chromosome 4 may be the result of decreased recombination.