Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada.
Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada.
Anal Biochem. 2020 Oct 1;606:113825. doi: 10.1016/j.ab.2020.113825. Epub 2020 Jul 23.
Alu elements, averaging ~300bp in length, are a family of primate-specific short intersperse nuclear elements (SINEs) with more than one million copies and contributing to ~11% of primate genomes. Despite mostly being shared among primates, our recent study revealed highly differential recent Alu transposition among the genomes of primates from Hominidae and Cercopithecidae families. To understand the underlying mechanism, we analyzed six primate genomes and revealed species- and lineage-specific Alu profile exclusively defined by AluY composition. Among all Alus from the 6 genomes, we identified 5401 Alu master copies with 99% being from the AluY subfamily. The numbers of Alu master copies are positively correlated to the number of AluY elements in the genomes with the baboon genome having the largest number of most recent Alu master copies at high activities, while the crab-eating macaque genome having a low number of Alu master copies with low activity. Furthermore, the expression level of Alu master copies is positively correlated with their transposition activity. Our results support the concept that Alu transposition in primate genomes is driven by a small number of master copies, the number and relative activity of which contribute to the differential Alu transposition in recent primate genomes.
Alu 元件平均长度约为 300bp，是一类灵长类特异性短散布核元件（SINEs），具有超过 100 万个拷贝，占灵长类基因组的约 11%。尽管它们主要在灵长类动物中共享，但我们最近的研究揭示了人科和猴科灵长类动物基因组中最近的 Alu 转座存在高度差异。为了了解其潜在机制，我们分析了 6 个灵长类动物基因组，并揭示了由 AluY 组成专门定义的物种和谱系特异性 Alu 特征。在 6 个基因组的所有 Alu 中，我们鉴定了 5401 个 Alu 主拷贝，其中 99%来自 AluY 亚家族。Alu 主拷贝的数量与基因组中 AluY 元件的数量呈正相关，狒狒基因组具有最高数量的最活跃的最近 Alu 主拷贝，而食蟹猴基因组具有数量较少但活性较低的 Alu 主拷贝。此外，Alu 主拷贝的表达水平与其转座活性呈正相关。我们的结果支持这样一种概念，即灵长类动物基因组中的 Alu 转座是由少数主拷贝驱动的，其数量和相对活性导致了最近灵长类动物基因组中 Alu 转座的差异。
