1School of Microbiology, University College Cork, Cork, Ireland.
2APC Microbiome Institute, University College Cork, Cork, Ireland.
Microb Genom. 2017 Jul 17;3(9):e000126. doi: 10.1099/mgen.0.000126. eCollection 2017 Sep.
, found in the intestinal microbiota of humans and animals, is studied as an example of the sub-dominant intestinal commensals that may impart benefits upon their host. Strains typically harbour at least one megaplasmid that encodes functions contributing to contingency metabolism and environmental adaptation. RNA sequencing (RNA-seq)transcriptomic analysis of strain UCC118 identified the presence of a novel unusually abundant long non-coding RNA (lncRNA) encoded by the megaplasmid, and which represented more than 75 % of the total RNA-seq reads after depletion of rRNA species. The expression level of this 520 nt lncRNA in UCC118 exceeded that of the 16S rRNA, it accumulated during growth, was very stable over time and was also expressed during intestinal transit in a mouse. This lncRNA sequence is specific to the species; however, among 45 genomes analysed, not all (only 34) harboured the sequence for the lncRNA. This lncRNA was produced in 27 tested strains, but at strain-specific expression levels. High-level lncRNA expression correlated with high megaplasmid copy number. Transcriptome analysis of a deletion mutant lacking this lncRNA identified altered expression levels of genes in a number of pathways, but a definitive function of this new lncRNA was not identified. This lncRNA presents distinctive and unique properties, and suggests potential basic and applied scientific developments of this phenomenon.
在人类和动物的肠道微生物群中发现的，被研究为可能赋予宿主益处的亚优势肠道共生菌的一个例子。这些菌株通常至少携带一个编码有助于应急代谢和环境适应功能的大质粒。对 UCC118 菌株的 RNA 测序（RNA-seq）转录组分析表明，存在一种新型的异常丰富的长非编码 RNA（lncRNA），由大质粒编码，在去除 rRNA 后，其代表了超过总 RNA-seq 读数的 75%。在 UCC118 中，这种 520nt 的 lncRNA 的表达水平超过了 16S rRNA，它在生长过程中积累，随着时间的推移非常稳定，并且在小鼠的肠道转运过程中也有表达。该 lncRNA 序列是特定于 物种的；然而，在分析的 45 个基因组中，并非所有（仅 34 个）都携带 lncRNA 的序列。该 lncRNA 在 27 个测试的 菌株中产生，但在菌株特异性表达水平上。高水平的 lncRNA 表达与高拷贝数的大质粒相关。缺失了这种 lncRNA 的突变体的转录组分析表明，许多途径中的基因表达水平发生了改变，但这种新 lncRNA 的明确功能尚未确定。这种 lncRNA 具有独特的特性，这表明这种现象具有潜在的基础和应用科学发展。
