Sherry S T, Harpending H C, Batzer M A, Stoneking M
Department of Anthropology, The Pennsylvania State University, University Park 16802, USA.
Genetics. 1997 Dec;147(4):1977-82. doi: 10.1093/genetics/147.4.1977.
There are estimated to be approximately 1000 members of the Ya5 Alu subfamily of retroposons in humans. This subfamily has a distribution restricted to humans, with a few copies in gorillas and chimpanzees. Fifty-seven Ya5 elements were previously cloned from a HeLa-derived randomly sheared total genomic library, sequenced, and screened for polymorphism in a panel of 120 unrelated humans. Forty-four of the 57 cloned Alu repeats were monomorphic in the sample and 13 Alu repeats were dimorphic for insertion presence/absence. The observed distribution of sample frequencies of the 13 dimorphic elements is consistent with the theoretical expectation for elements ascertained in a single diploid cell line. Coalescence theory is used to compute expected total pedigree branch lengths for monomorphic and dimorphic elements, leading to an estimate of human effective population size of approximately 18,000 during the last one to two million years.
据估计，人类中反转座子Ya5 Alu亚家族约有1000个成员。该亚家族的分布仅限于人类，在大猩猩和黑猩猩中只有少数拷贝。先前从一个源自HeLa的随机剪切的全基因组文库中克隆了57个Ya5元件，进行了测序，并在120名无亲缘关系的人类群体中筛选了多态性。57个克隆的Alu重复序列中有44个在样本中是单态的，13个Alu重复序列在插入存在/缺失方面是双态的。观察到的13个双态元件的样本频率分布与在单个二倍体细胞系中确定的元件的理论预期一致。合并理论用于计算单态和双态元件的预期总谱系分支长度，从而估计出在过去100万到200万年中人类有效种群大小约为18000。
