Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA.
RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, USA.
Nat Commun. 2022 Feb 11;13(1):837. doi: 10.1038/s41467-022-28482-7.
Small RNA pathways play key and diverse regulatory roles in C. elegans, but our understanding of their conservation and contributions in other nematodes is limited. We analyzed small RNA pathways in the divergent parasitic nematode Ascaris. Ascaris has ten Argonautes with five worm-specific Argonautes (WAGOs) that associate with secondary 5'-triphosphate 22-24G-RNAs. These small RNAs target repetitive sequences or mature mRNAs and are similar to the C. elegans mutator, nuclear, and CSR-1 small RNA pathways. Even in the absence of a piRNA pathway, Ascaris CSR-1 may still function to "license" as well as fine-tune or repress gene expression. Ascaris ALG-4 and its associated 26G-RNAs target and likely repress specific mRNAs during testis meiosis. Ascaris WAGO small RNAs demonstrate target plasticity changing their targets between repeats and mRNAs during development. We provide a unique and comprehensive view of mRNA and small RNA expression throughout spermatogenesis. Overall, our study illustrates the conservation, divergence, dynamics, and flexibility of small RNA pathways in nematodes.
小 RNA 通路在秀丽隐杆线虫中发挥着关键且多样化的调控作用，但我们对其在其他线虫中的保守性和作用的理解还很有限。我们分析了分化的寄生线虫蛔虫中的小 RNA 通路。蛔虫有十个 Argonautes，其中五个是与二级 5'-三磷酸 22-24G-RNAs 相关的线虫特异性 Argonautes（WAGOs）。这些小 RNA 靶向重复序列或成熟的 mRNA，与秀丽隐杆线虫 mutator、核和 CSR-1 小 RNA 通路相似。即使没有 piRNA 通路，蛔虫 CSR-1 可能仍然具有“许可”以及微调或抑制基因表达的功能。蛔虫 ALG-4 及其相关的 26G-RNAs 在睾丸减数分裂过程中靶向并可能抑制特定的 mRNA。蛔虫 WAGO 小 RNA 在发育过程中表现出靶标可塑性，在重复序列和 mRNA 之间改变其靶标。我们提供了一个独特而全面的视角，展示了线虫中 mRNA 和小 RNA 表达在整个精子发生过程中的变化。总的来说，我们的研究说明了小 RNA 通路在线虫中的保守性、分化、动态和灵活性。
