Lloyd J A, Lamb A N, Potter S S
Children's Hospital Research Foundation, Cincinnati, Ohio 45229.
Mol Biol Evol. 1987 Mar;4(2):85-98. doi: 10.1093/oxfordjournals.molbev.a040429.
The phi-screen, a method of phylogenetic screening, can be employed to detect repetitive sequence families that differentially hybridize between closely related species. Such differences may involve sequence divergence or variations in copy number, including total presence versus absence of a family of repeated DNA. We present the results of a phi-screen comparing the human genome to that of the prosimian, Galago crassicaudatus. Three human repetitive families that are divergent or not present in galago have been detected. One of these families is described in detail; it is similar among the anthropoids but is present in a lower copy number and/or divergent form in prosimians. The family is clearly related to the transposon-like human element (THE) described by Paulson et al. (1985). THEs have long terminal repeats reminiscent of retroviruses but are unique in that they have no sequence similarity to known mammalian retroviruses. The sequence of a solo long terminal repeat, found unassociated with THE internal sequence, is presented. This family member, THE p2, is bordered by a 5-bp target-site repeat and is interrupted by the insertion of an Alu element. A solo THE element sequenced by Wiginton et al. (1986) contains an insertion of Alu at precisely the same position as does THE p2.
φ筛选是一种系统发育筛选方法，可用于检测在亲缘关系密切的物种之间差异杂交的重复序列家族。这种差异可能涉及序列分歧或拷贝数变异，包括重复DNA家族的完全存在或缺失。我们展示了将人类基因组与原猴类粗尾婴猴（Galago crassicaudatus）基因组进行φ筛选的结果。已检测到三个在婴猴中存在分歧或不存在的人类重复家族。其中一个家族被详细描述；它在类人猿中相似，但在原猴类中的拷贝数较低和/或呈分歧形式。该家族显然与保尔森等人（1985年）描述的类转座子人类元件（THE）相关。THE具有类似于逆转录病毒的长末端重复序列，但独特之处在于它们与已知的哺乳动物逆转录病毒没有序列相似性。展示了一个与THE内部序列无关的单独长末端重复序列的序列。这个家族成员THE p2，由一个5碱基对的靶位点重复序列界定，并被一个Alu元件的插入打断。威金顿等人（1986年）测序的一个单独THE元件在与THE p2完全相同的位置包含一个Alu插入。
