Murray J C, Mills K A, Demopulos C M, Hornung S, Motulsky A G
Proc Natl Acad Sci U S A. 1984 Jun;81(11):3486-90. doi: 10.1073/pnas.81.11.3486.
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.
已鉴定出另外四个DNA变异体（限制性酶切片段长度多态性），使得人类白蛋白基因座共有八个多态性位点。通过使用白蛋白的cDNA探针和27种不同的限制性酶对20,000个核苷酸中的689个进行筛选后发现了这八个位点。因此，每85个核苷酸中就有一个可能是多态性的。任意两个随机选择的染色体之间的平均核苷酸多样性经计算为1/500。我们观察到这八个变异体之间存在明显的连锁不平衡。在来自白种人、黑人和亚洲人的160条染色体中，在256种可能的组合中仅观察到7种单倍型。在所有三个人种中都发现了两种单倍型，这表明它们的起源早于人类种族分化。三种最罕见的单倍型似乎代表了较常见单倍型之间的重组事件。所有交叉都发生在同一大致区域。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化。尽管无法排除通过选择或固定来维持这种紧密连锁的可能性，但有人认为，在靠近4号染色体着丝粒的白蛋白基因染色体位点处单倍型数量有限可能是重组减少的结果。
