Department of Microbiology and Parasitology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, #5 Dong Dan San Tiao, Beijing, 100005, People's Republic of China.
NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
Parasit Vectors. 2021 Jan 29;14(1):87. doi: 10.1186/s13071-020-04570-9.
Small non-coding RNAs play critical regulatory roles in post-transcription. However, their characteristics in Trichomonas vaginalis, the causative agent of human sexually transmitted trichomoniasis, still remain to be determined.
Small RNA transcriptomes from Trichomonas trophozoites were deep sequenced using the Illumina NextSeq 500 system and comprehensively analyzed to identify Trichomonas microRNAs (miRNAs) and transfer RNA (tRNA)-derived small RNAs (tsRNAs). The tsRNA candidates were confirmed by stem-loop quantitative reverse transcription-PCR, and motifs to guide the cleavage of tsRNAs were predicted using the GLAM2 algorithm.
The miRNAs were found to be present in T. vaginalis but at an extremely low abundance (0.0046%). Three categories of endogenous Trichomonas tsRNAs were identified, namely 5'tritsRNAs, mid-tritsRNAs and 3'tritsRNAs, with the 5'tritsRNAs constituting the dominant category (67.63%) of tsRNAs. Interestingly, the cleavage site analysis verified both conventional classes of tRNA-derived fragments (tRFs) and tRNA-halves in tritsRNAs, indicating the expression of tRNA-halves in the non-stress condition. A total of 25 tritsRNAs were experimentally confirmed, accounting for 78.1% of all tested candidates. Three motifs were predicted to guide the production of tritsRNAs. The results prove the expression of tRFs and tRNA-halves in the T. vaginalis transcriptome.
This is the first report of genome-wide investigation of small RNAs, particularly tsRNAs and miRNAs, from Trichomonas parasites. Our findings demonstrate the expression profile of tsRNAs in T. vaginalis, while miRNA was barely detected. These results may promote further research aimed at gaining a better understanding of the evolution of small non-coding RNA in T. vaginalis and their functions in the pathogenesis of trichomoniasis.
小非编码 RNA 在转录后发挥关键的调控作用。然而，它们在阴道毛滴虫中的特征，阴道毛滴虫是导致人类性传播滴虫病的病原体，仍有待确定。
使用 Illumina NextSeq 500 系统对阴道毛滴虫滋养体的小 RNA 转录组进行深度测序，并进行全面分析，以鉴定阴道毛滴虫 microRNAs (miRNAs) 和转移 RNA (tRNA)衍生的小 RNA (tsRNAs)。通过茎环定量逆转录 PCR 确认 tsRNA 候选物，并使用 GLAM2 算法预测指导 tsRNA 切割的基序。
发现 miRNAs 存在于阴道毛滴虫中，但丰度极低 (0.0046%)。鉴定出三种内源性阴道毛滴虫 tsRNAs，即 5'tritsRNAs、mid-tritsRNAs 和 3'tritsRNAs，其中 5'tritsRNAs 构成 tsRNAs 的主要类别 (67.63%)。有趣的是，切割位点分析验证了 tritsRNAs 中常规的两类 tRNA 衍生片段 (tRFs) 和 tRNA 一半，表明在非应激条件下表达 tRNA 一半。共实验验证了 25 个 tritsRNAs，占所有测试候选物的 78.1%。预测了三个基序来指导 tritsRNAs 的产生。结果证明了 tRFs 和 tRNA 一半在阴道毛滴虫转录本中的表达。
这是首次对阴道毛滴虫小 RNA，特别是 tsRNAs 和 miRNAs 的全基因组研究报告。我们的发现表明了 tsRNAs 在阴道毛滴虫中的表达谱，而 miRNA 几乎检测不到。这些结果可能促进进一步研究，以更好地了解小非编码 RNA 在阴道毛滴虫中的进化及其在滴虫病发病机制中的功能。
