Kuryshev V Y, Skryabin B V, Kremerskothen J, Jurka J, Brosius J
Institute of Experimental Pathology/Molecular Neurobiology, ZMBE, University of Münster, Von-Esmarch-Str. 56, Münster, D-48149, Germany.
J Mol Biol. 2001 Jun 22;309(5):1049-66. doi: 10.1006/jmbi.2001.4725.
The gene encoding brain-specific dendritic BC200 small non-messenger RNA is limited to the primate order and arose from a monomeric Alu element. It is present and neuronally expressed in all Anthropoidea examined. By comparing the human sequence of about 13.2 kb with each of the prosimian (lemur 14.6 kb, galago 12 kb, and tarsier 13.8 kb) orthologous loci, we could establish that the BC200 RNA gene is absent from the prosimian lineages. In Strepsirhini (lemurs and lorises), a dimeric AluJ-like element integrated very close to the BC200 insertion point, while the corresponding tarsier region is devoid of any repetitive element. Consequently, insertion of the Alu monomer that gave rise to the BC200 RNA gene must have occurred after the anthropoid lineage diverged from the prosimian lineage(s). Shared insertions of other repetitive elements favor proximity of simians and tarsiers in support of their grouping into Haplorhini and the omomyid hypothesis. On the other hand, the nucleotide sequences in the segment that is available for comparison in all four species reveal less exchanges between Strepsirhini (lemur and galago) and human than between tarsier and human. Our data imply that the early activity of dimeric Alu sequences must have been concurrent with the activity of monomeric Alu elements that persisted longer than is usually thought. As BC200 RNA gave rise to more than 200 pseudogenes, we used their consensus sequence variations as a molecular archive recording the BC200 RNA sequence changes in the anthropoid lineage leading to Homo sapiens and timed these alterations over the past 35-55 million years.
编码脑特异性树突状BC200小非信使RNA的基因仅限于灵长目，起源于一个单体Alu元件。在所研究的所有类人猿中均存在并在神经元中表达。通过将约13.2 kb的人类序列与每个原猴亚目（狐猴14.6 kb、婴猴12 kb和眼镜猴13.8 kb）的直系同源位点进行比较，我们可以确定原猴亚目谱系中不存在BC200 RNA基因。在原猴亚目（狐猴和懒猴）中，一个二聚体AluJ样元件整合在非常靠近BC200插入点的位置，而相应的眼镜猴区域没有任何重复元件。因此，产生BC200 RNA基因的Alu单体的插入一定发生在类人猿谱系与原猴亚目谱系分化之后。其他重复元件的共享插入有利于猿猴和眼镜猴的接近，支持它们被归为简鼻亚目以及始镜猴假说。另一方面，在所有四个物种中可比较的片段中的核苷酸序列显示，原猴亚目（狐猴和婴猴）与人类之间的交换比眼镜猴与人类之间的交换少。我们的数据表明，二聚体Alu序列的早期活性一定与持续时间比通常认为的更长的单体Alu元件的活性同时存在。由于BC200 RNA产生了200多个假基因，我们将它们的共有序列变异用作一个分子档案，记录在导致智人的类人猿谱系中BC200 RNA序列的变化，并确定了这些变化在过去3500万至5500万年中的时间。
