Expression profile analysis of circular RNAs in BmN cells (Bombyx mori) upon BmNPV infection

Abstract

The disease caused by Bombyx mori nucleopolyhedrovirus (BmNPV) has always been difficult to control, resulting in tremendous economic losses in the sericulture industry. Although much has been learned about the impact of noncoding RNAs on pathogenesis, the role of circular RNA (circRNA) in insect immunity remains unclear. To explore circRNA regulation involved in BmNPV infection, we used transcriptome analysis of BmN cells with or without BmNPV infection to generate circRNA data set. A total of 444 novel circRNAs were identified in BmN cells, with 198 pervasively distributed both in the control group and BmNPV-infection group. The host genes were enriched inMAPK signaling pathway, dorso-ventral axis formation, and ECM-receptor interaction, which were required for the normal larval growth. A total of 75 circRNAs were differentially expressed (DE) on BmNPV infection. Six downregulated circRNAs were validated by Sanger sequencing and qRT-PCR. DEcircRNA-miRNA-DEmRNA network was constructed based on the six validated cir-cRNAs. Pathway analysis indicated that the predicted target genes were mainly enriched in the metabolic pathway and immune-related signaling pathway. Our results may provide a basis for further studies on circRNA function in BmN cells challenged by BmNPV infection and offer an

Aal-circRNA-407 regulates ovarian development of Aedes albopictus, a major arbovirus vector, via the miR-9a-5p/Foxl axis

“…The above characteristics suggested that circRNAs in Ae . albopictus were similar to those identified in other insect species [ 17 – 19 , 67 ], and some circRNAs were even conserved between mosquitoes and fruit flies.…”

“…Interestingly, the highly expressed circRNAs in Drosophila [66] were also present in our circRNA-seq data, and further RT-PCR amplification followed by Sanger sequencing using divergent primers confirmed the existence of the predicted BSJ (S5E-S5H Fig) . The above characteristics suggested that circRNAs in Ae. albopictus were similar to those identified in other insect species [17][18][19]67], and some circRNAs were even conserved between mosquitoes and fruit flies.…”

The Potential Biological Roles of Circular RNAs in the Immune Systems of Insects to Pathogen Invasion

“…B. mori nucleopolyhedrovirus (BmNPV) causes diseases that have always been difficult to control, resulting in tremendous economic losses in the sericulture industry [ 83 , 84 ]. It has been proposed that BmNPV proliferation within host cells is mediated by a cascade of viral gene expression, and identifying host genes that respond to BmNPV infection is a promising strategy for developing BmNPV-resistant silkworms [ 85 , 86 ].…”

“…It has been proposed that BmNPV proliferation within host cells is mediated by a cascade of viral gene expression, and identifying host genes that respond to BmNPV infection is a promising strategy for developing BmNPV-resistant silkworms [ 85 , 86 ]. Despite this, several recent studies have investigated the effect of circRNA involvement in BmNPV infection [ 81 , 84 , 87 ]. It has been demonstrated that after BmNPV infection, the expression levels of circRNAs in the silkworm midgut are altered, and these dysregulated circRNAs may play roles in BmNPV infection, implying that these altered circRNAs may be a novel type of anti-viral factor [ 88 ].…”