Control of spring viremia of carp in common carp using RNA interference

• Published in: Aquaculture Vol. 559; p. 738417
• Main Authors: Fouad, Alamira Marzouk, Elkamel, Ahmad A., Ibrahim, Sherif, El-Matbouli, Mansour, Soliman, Hatem, Abdallah, Ebtsam Sayed Hassan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2022
• Subjects: Carp sprivivirus; Control; Gene silencing; In-vivo RNAi; Virus replication; Carp sprivivirus; Gene silencing; Control; Virus replication; In-vivo RNAi
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2022.738417

In this study, the control of Carp sprivivirus, commonly known as spring viremia of carp virus (SVCV), replication in Epithelioma papulosum cyprini (EPC) cells and for the first time in common carp was investigated by using the RNA interference (RNAi) technology targeting the glycoprotein (G), matrix protein (M), and RNA-dependent RNA polymerase (L) genes. Small-interfering RNA sequences (siRNAs) were selected to target three different regions on both the SVCV-G (G-102, G-1070, and G-1456) and SVCV-M gene (M-88, M-271, and M-414). Designed specific siRNAs were investigated individually or in combinations in EPC cells. In vitro results showed that the most effective siRNAs were G-102 and M-271 that significantly reduced the virus titer in EPC cells by 1.6 logs and 1.5 logs respectively. Various combinations of the G-102 and M-271 of this study and siRNA-L-602 (targets the L-gene) from our previous study were investigated in vitro. Results showed that the most effective combination in reducing the virus replication in EPC cells was the siRNA-M-271 + L-602 combination as indicated by the significant reduction in virus titer (2.9 logs). In-vivo investigation of the siRNA-M-271 + L-602 combination by single or two successive doses in common carp challenged by IP injection of SVCV showed a significant reduction in mortality rate by 77.78% and 88.89% respectively. Results were confirmed by measuring the downregulation of SVCV-M and -L gene expression in vivo. Results of this study proved that SVCV can be controlled in common carp through targeting the SVCV-M and -L genes by using the RNAi technology that results in a significant in-vivo reduction of the SVCV replication. •RNAi inhibit SVCV replication both in-vitro & in-vivo.•Targeting M & L genes with siRNA significantly reduce SVCV titer in EPC cells.•Two-successive siRNA doses reduce mortality rate in SVCV-challenged common carp.