Quentin Y
Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, NM 87545.
Nucleic Acids Res. 1992 Feb 11;20(3):487-93. doi: 10.1093/nar/20.3.487.
In the primate genome, a typical Alu element corresponds to a dimeric structure composed of two different but related monomeric sequences arranged in tandem. However, the analysis of primate sequences found in GenBank reveals the presence of free left and free right Alu elements. Here, we report the statistical study of those monomeric elements. We found that only a small fraction of them results from a deletion of a dimeric Alu sequence. The majority derives from the amplification of monomeric progenitor sequences and constitutes two families of monomeric elements: a family of free left Alu monomers that is composed of two subfamilies and a small family of free right Alu monomers. Both families predated the dimeric Alu elements, and a phylogenetic analysis strongly suggests that the first progenitor of the dimeric Alu family arose through the fusion of a free left monomer with a free right monomer.
在灵长类动物基因组中，一个典型的Alu元件对应于一种由两个不同但相关的单体序列串联排列组成的二聚体结构。然而，对GenBank中灵长类序列的分析揭示了游离的左Alu元件和游离的右Alu元件的存在。在此，我们报告对这些单体元件的统计研究。我们发现，其中只有一小部分是由二聚体Alu序列缺失产生的。大多数来自单体祖源序列的扩增，并构成了两个单体元件家族：一个由两个亚家族组成的游离左Alu单体家族和一个小的游离右Alu单体家族。这两个家族都早于二聚体Alu元件，系统发育分析强烈表明，二聚体Alu家族的第一个祖源是通过一个游离左单体与一个游离右单体的融合产生的。
