Cloning and transplantation of bacterial genomes is a powerful method for the creation of engineered microorganisms. However, much remains to be understood about the molecular mechanisms and limitations of this approach. We report the whole-genome cloning of Mesoplasma florum in Saccharomyces cerevisiae, and use this model to investigate the impact of a bacterial chromosome in yeast cells. Our results indicate that the cloned M. florum genome is subjected to weak transcriptional activity, and causes no significant impact on yeast growth. We also report that the M. florum genome can be transplanted into Mycoplasma capricolum without any negative impact from the putative restriction enzyme encoding gene mfl307. Using whole-genome sequencing, we observed that a small number of mutations appeared in all M. florum transplants. Mutations also arose, albeit at a lower frequency, when the M. capricolum genome was transplanted into M. capricolum recipient cells. These observations suggest that genome transplantation is mutagenic, and that this phenomenon is magnified by the use of genome donor and recipient cell belonging to different species. No difference in efficiency was detected after three successive rounds of genome transplantation, suggesting that the observed mutations were not selected during the procedure. Taken together, our results provide a more accurate picture of the events taking place during bacterial genome cloning and transplantation.

中文翻译：

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中型花rum基因组的克隆与移植

细菌基因组的克隆和移植是创建工程微生物的强大方法。但是，关于这种方法的分子机理和局限性，还有很多地方要理解。我们报告的全基因组克隆的Mesoplasma florum在酿酒酵母，并用这个模型来观察细菌染色体在酵母细胞的影响。我们的结果表明，克隆的弗洛姆氏菌基因组具有弱的转录活性，并且对酵母菌的生长没有明显的影响。我们还报告说，M。florum基因组可以被移植到山羊支原体中，而不受假定的限制性酶编码基因的任何负面影响。mfl307。使用全基因组测序，我们观察到在所有弗洛姆氏菌移植物中均出现少量突变。当Capricolum基因组被移植到M. capricolum中时，突变也出现，尽管频率较低。受体细胞。这些观察结果表明基因组移植是诱变的，并且通过使用属于不同物种的基因组供体和受体细胞而放大了这种现象。在连续三轮基因组移植后未检测到效率差异，表明在此过程中未选择观察到的突变。两者合计，我们的结果提供了细菌基因组克隆和移植过程中发生的事件的更准确的图片。