Hudson R R, Kaplan N L
National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Genetics. 1988 Nov;120(3):831-40. doi: 10.1093/genetics/120.3.831.
The statistical properties of the process describing the genealogical history of a random sample of genes at a selectively neutral locus which is linked to a locus at which natural selection operates are investigated. It is found that the equations describing this process are simple modifications of the equations describing the process assuming that the two loci are completely linked. Thus, the statistical properties of the genealogical process for a random sample at a neutral locus linked to a locus with selection follow from the results obtained for the selected locus. Sequence data from the alcohol dehydrogenase (Adh) region of Drosophila melanogaster are examined and compared to predictions based on the theory. It is found that the spatial distribution of nucleotide differences between Fast and Slow alleles of Adh is very similar to the spatial distribution predicted if balancing selection operates to maintain the allozyme variation at the Adh locus. The spatial distribution of nucleotide differences between different Slow alleles of Adh do not match the predictions of this simple model very well.
研究了描述与自然选择起作用的位点相连的选择中性位点上随机基因样本系谱历史的过程的统计特性。发现描述该过程的方程是对假设两个位点完全连锁时描述该过程的方程的简单修改。因此,与有选择作用的位点相连的中性位点上随机样本的系谱过程的统计特性可从所选位点获得的结果推导出来。对黑腹果蝇乙醇脱氢酶(Adh)区域的序列数据进行了检查,并与基于该理论的预测进行了比较。发现Adh的快等位基因和慢等位基因之间核苷酸差异的空间分布与如果平衡选择起作用以维持Adh位点的同工酶变异时预测的空间分布非常相似。Adh不同慢等位基因之间核苷酸差异的空间分布与这个简单模型的预测不太匹配。