Musich P R, Dykes R J
Proc Natl Acad Sci U S A. 1986 Jul;83(13):4854-8. doi: 10.1073/pnas.83.13.4854.
Several human DNAs digested with Kpn I restriction endonuclease released a 0.6-kilobase (kb) segment that varied in its intensity among human samples. A recombinant DNA clone (N6.4) of these 0.6-kb Kpn I segments was isolated and used to probe the genomic content and restriction cleavage pattern of homologous sequences. The hybridization patterns revealed a previously undescribed, moderately repetitive long interspersed (LINE) sequence family, which we have termed L2Hs (second LINE family in Homo sapiens). This LINE family exhibits both quantitative and qualitative polymorphisms in the human population. The content of L2Hs sequences in human genomes varies over a 5-fold range. Relative to the value for a human placental DNA, sequences homologous to the L2Hs family occur in lower amounts in gorilla DNA (approximately 20%) and even less in DNA from chimpanzees and other primates (less than 1%). Thus, the L2Hs sequences appear to have emerged only recently as a moderately repetitive sequence family in primate evolution. The observed restriction fragment length polymorphism of the L2Hs family members may reflect patterns of sequence rearrangements, amplifications, and/or deletions in human genomes.
几种经Kpn I限制性内切酶消化的人类DNA释放出一个0.6千碱基（kb）的片段，该片段在不同人类样本中的强度有所不同。分离出这些0.6 kb Kpn I片段的一个重组DNA克隆（N6.4），并用于探测同源序列的基因组含量和限制性切割模式。杂交模式揭示了一个以前未描述过的、中度重复的长散在（LINE）序列家族，我们将其命名为L2Hs（智人中的第二个LINE家族）。这个LINE家族在人类群体中表现出数量和质量上的多态性。人类基因组中L2Hs序列的含量在5倍的范围内变化。相对于人类胎盘DNA的值，与L2Hs家族同源的序列在大猩猩DNA中的含量较低（约20%），在黑猩猩和其他灵长类动物的DNA中含量更低（不到1%）。因此，L2Hs序列似乎是在灵长类动物进化过程中最近才作为一个中度重复序列家族出现的。观察到的L2Hs家族成员的限制性片段长度多态性可能反映了人类基因组中序列重排、扩增和/或缺失的模式。
