Key Laboratory of Zoological Systematics and Evolution & State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Key Laboratory of Zoological Systematics and Evolution & State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Genet Genomics. 2023 Jul;50(7):462-472. doi: 10.1016/j.jgg.2023.04.003. Epub 2023 Apr 15.
Since the discovery of the first transposon by Dr. Barbara McClintock, the prevalence and diversity of transposable elements (TEs) have been gradually recognized. As fundamental genetic components, TEs drive organismal evolution not only by contributing functional sequences (e.g., regulatory elements or "controllers" as phrased by Dr. McClintock) but also by shuffling genomic sequences. In the latter respect, TE-mediated gene duplications have contributed to the origination of new genes and attracted extensive interest. In response to the development of this field, we herein attempt to provide an overview of TE-mediated duplication by focusing on common rules emerging across duplications generated by different TE types. Specifically, despite the huge divergence of transposition machinery across TEs, we identify three common features of various TE-mediated duplication mechanisms, including end bypass, template switching, and recurrent transposition. These three features lead to one common functional outcome, namely, TE-mediated duplicates tend to be subjected to exon shuffling and neofunctionalization. Therefore, the intrinsic properties of the mutational mechanism constrain the evolutionary trajectories of these duplicates. We finally discuss the future of this field including an in-depth characterization of both the duplication mechanisms and functions of TE-mediated duplicates.
自芭芭拉·麦克林托克（Barbara McClintock）博士发现第一个转座子以来，转座元件（TEs）的普遍性和多样性逐渐得到了认识。作为基本的遗传成分，TEs 通过贡献功能序列（例如，调控元件或麦克林托克博士所说的“控制器”）以及通过重排基因组序列来驱动生物进化。在后一方面，TE 介导的基因复制有助于新基因的产生，并引起了广泛的关注。为了应对这一领域的发展，我们在此试图通过关注由不同 TE 类型产生的重复所出现的常见规则，来提供一个关于 TE 介导的重复的概述。具体来说，尽管转座机制在 TE 之间存在巨大的差异，但我们确定了三种常见的 TE 介导的重复机制，包括末端绕过、模板切换和反复转座。这三个特征导致了一个共同的功能结果，即 TE 介导的重复往往会受到外显子改组和新功能化的影响。因此，突变机制的内在特性限制了这些重复的进化轨迹。我们最后讨论了这一领域的未来，包括对 TE 介导的重复的复制机制和功能进行深入的特征描述。
