A SIMPLE GENEALOGICAL STRUCTURE OF STRONGLY BALANCED ALLELIC LINES AND TRANSSPECIES EVOLUTION OF POLYMORPHISM
A SIMPLE GENEALOGICAL STRUCTURE OF STRONGLY BALANCED ALLELIC LINES AND TRANSSPECIES EVOLUTION OF POLYMORPHISM
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DOI：
10.1073/pnas.87.7.2419
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发表时间：
1990-04-01
影响因子：
11.1
通讯作者：
TAKAHATA, N
中科院分区：
文献类型：
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作者：
TAKAHATA, N
不同的等位基因进行强对称平衡选择显示出一个简单的系谱结构（等位基因系谱），类似于中性基因的样本随机抽取的panmictic人口在平衡的聚结过程所描述的基因系谱。这两个家谱的唯一区别在于不同的时间尺度。等位基因谱系相对于中性基因谱系的近似比例因子为{sqroot S/（2 M）} cnt dot。[ln}S/（16 π M2）}]-3/2，其中M = Nu且S = 2Ns（N，有效群体大小; u，每代每个基因座对所选等位基因的突变率; s，选择系数）。平方根S/M（≤ 100）的值越大，比例因子越大。这些研究结果，支持模拟结果，允许一个应用的理论结果的聚结过程中直接的等位基因系谱。结合主要组织相容性复合体多态性的跨物种进化，平衡选择被认为是负责的，等位基因系谱学预测，在人类种群中繁殖个体的数量不可能在其进化历史的任何时候都是50-100个。这项分析似乎与创始人原则相矛盾，因为创始人原则在最近的哺乳动物进化中很重要。
Different alleles undergoing strong symmetric balancing selection show a simple genealogical structure (allelic genealogy), similar to the gene genealogy described by the coalescence process for a sample of neutral genes randomly drawn from a panmictic population at equilibrium. The only difference between the two genealogies lies in the different time scales. An approximate scaling factor for allelic genealogy relative to that of neutral gene genealogy is {.sqroot.S/(2M)} .cntdot. [ln}S/(16.pi.M2)}]-3/2, where M = Nu and S = 2Ns (N, effective population size; u, mutation rate to selected alleles per locus per generation; s, selection coefficient). The larger the value of .sqroot.S/M (.ltoreq.100), the larger the scaling factor. These findings, supported by simulation results, allow one to apply the theoretical results of the coalescence process directly to the allelic genealogy. Combined with the trans-species evolution of the major histocompatibility complex polymorphism for which balancing selection is believed to be responsible, allelic genealogy predicts that the number of breeding individuals in the human population could not be a small as 50-100 at any time of its evolutionary history. The analysis appears to contradict the founder principle as being important in recent mammalian evolution.