Singh Chandra Pal
Department of Botany, University of Rajasthan, Jaipur-302004, Rajasthan, India.
Microrna. 2021;10(1):3-13. doi: 10.2174/2211536610666210121154314.
The mulberry silkworm Bombyx mori, apart from its well-known economic importance, has also emerged as an insect model to study host-pathogen interactions. The major concern for silkworm cultivation and the sericulture industry is the attack by various types of pathogens mainly including viruses, fungi, bacteria and protozoa. Successful infection requires specific arsenals to counter the host immune response. MicroRNAs (miRNAs) are one of the potential arsenals which are encoded by viruses and effectively used during host-pathogen interactions. MiRNAs are short noncoding 19-25 nucleotides long endogenous RNAs that post-transcriptionally regulate the expression of protein-coding genes in a sequence-specific manner. Most of the higher eukaryotes encode miRNAs and utilize them in the regulation of important cellular pathways. In silkworm, promising functions of miRNAs have been characterized in development, metamorphosis, immunity, and host-pathogen interactions. The viral miRNA-mediated fine-tuning of the viral, as well as cellular genes, is beneficial for making a cellular environment favorable for the virus proliferation. Baculovirus and cypovirus, which infect silkworm have been shown to encode miRNAs and their functions are implicated in controlling the expression of both viral and host genes. In the present review, the author discusses the diverse functions of viral-encoded miRNAs in evasion of the host immune responses and reshaping of the silkworm cellular environment for replication. Besides, a basic overview of miRNA biogenesis and mechanism of action is also provided. Our increasing understanding of the role of viral miRNAs in silkworm-virus interactions would not only assist us to get insights into the intricate pathways but also provide tools to deal with dreaded pathogens.
家蚕（Bombyx mori）除了具有众所周知的经济重要性外，还已成为研究宿主 - 病原体相互作用的昆虫模型。家蚕养殖和养蚕业面临的主要问题是受到各种病原体的侵袭，这些病原体主要包括病毒、真菌、细菌和原生动物。成功感染需要特定的手段来对抗宿主的免疫反应。微小RNA（miRNA）是病毒编码的潜在手段之一，在宿主 - 病原体相互作用过程中被有效利用。miRNA是长度为19 - 25个核苷酸的短非编码内源性RNA，它们以序列特异性方式在转录后调节蛋白质编码基因的表达。大多数高等真核生物都编码miRNA，并利用它们来调节重要的细胞途径。在家蚕中，miRNA在发育、变态、免疫和宿主 - 病原体相互作用中具有有前景的功能。病毒miRNA介导的对病毒以及细胞基因的微调，有利于营造有利于病毒增殖的细胞环境。已证明感染家蚕的杆状病毒和质型多角体病毒编码miRNA，其功能与控制病毒和宿主基因的表达有关。在本综述中，作者讨论了病毒编码的miRNA在逃避宿主免疫反应和重塑家蚕细胞环境以进行复制方面的多种功能。此外，还提供了miRNA生物合成和作用机制的基本概述。我们对病毒miRNA在家蚕 - 病毒相互作用中作用的日益了解，不仅将帮助我们深入了解复杂的途径，还将提供应对可怕病原体的工具。
