Title:Viral-Encoded microRNAs in Host-Pathogen Interactions in Silkworm
VOLUME: 10 ISSUE: 1
Author(s):Chandra Pal Singh*
Affiliation:Department of Botany, University of Rajasthan, Jaipur-302004, Rajasthan
Keywords:MicroRNA, virus, silkworm, Bombyx mori, insect and host-pathogen interactions, siRNAs.
Abstract: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.
