Toro Nicolás, Martínez-Abarca Francisco, Molina-Sánchez María D, García-Rodríguez Fernando M, Nisa-Martínez Rafael
Structure, Dynamics and Function of Rhizobacterial Genomes (Grupo de Ecología Genética de la Rizosfera), Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain.
Front Microbiol. 2018 Apr 4;9:627. doi: 10.3389/fmicb.2018.00627. eCollection 2018.
Mobile group II introns are ribozymes and retroelements that probably originate from bacteria. , the nitrogen-fixing endosymbiont of legumes of genus , harbors a large number of these retroelements. One of these elements, RmInt1, has been particularly successful at colonizing this multipartite genome. Many studies have improved our understanding of RmInt1 and phylogenetically related group II introns, their mobility mechanisms, spread and dynamics within and closely related species. Although RmInt1 conserves the ancient retroelement behavior, its evolutionary history suggests that this group II intron has played a role in the short- and long-term evolution of the genome. We will discuss its proposed role in genome evolution by controlling the spread and coexistence of potentially harmful mobile genetic elements, by ectopic transposition to different genetic loci as a source of early genomic variation and by generating sequence variation after a very slow degradation process, through intron remnants that may have continued to evolve, contributing to bacterial speciation.
移动II组内含子是可能起源于细菌的核酶和反转录元件。豆科植物根瘤菌属的固氮内共生体中含有大量此类反转录元件。其中一个元件RmInt1在定殖于这个多分体基因组方面特别成功。许多研究增进了我们对RmInt1以及系统发育相关的II组内含子、它们的移动机制、在根瘤菌及其近缘物种中的传播和动态变化的理解。尽管RmInt1保留了古老的反转录元件行为，但其进化历史表明这个II组内含子在根瘤菌基因组的短期和长期进化中发挥了作用。我们将讨论它在基因组进化中所提出的作用，包括通过控制潜在有害的移动遗传元件的传播和共存，通过异位转座到不同基因位点作为早期基因组变异的来源，以及通过在一个非常缓慢的降解过程后产生序列变异，该过程通过可能持续进化的内含子残余物来实现，这有助于细菌物种形成。
