Effect of in vitro passage on virulence of largemouth bass (Micropterus salmoides) ranavirus
WANG Congxu，PAN Xiaoyi，ZHOU Kexin，MU Xuejiao，YAO Jiayun，LIN Lingyun，ZHAO Jianhua，SHEN Jinyu*
1.College of Life Sciences，Huzhou University，Huzhou 313001，China；2. Key Laboratory of Healthy Freshwater Aquaculture，Ministry of Agriculture and Rural Affairs，Key Laboratory of Fish Health and Nutrition of Zhejiang Province，Zhejiang Institute of Freshwater Fisheries，Huzhou 313001，China
Abstract: The challenge test was conducted in largemouth bass (Micropterussalmoides) with body weight of (14±2)g to investigate the virulence of largemouth bass ranavirus (LMBV) in different generations. The growth kinetics of the LMBV virus were established with different titers by tissue culture infectious dose (TCID50) method, and the viral load was collected in tissue samples 1, 6, 12, 24, 36, 48, 72, 96, 120, 144, and 168 h after the challenge. The whole-genome sequences of F5 and F65 were obtained by next-generation sequencing and four virulence genes were screened out for the analysis of other genes from different strains. The results showed that lethality were found to be 60% in F5, 25% in F35 and 5% in F65 after challenge with 108.5 TCID50/mL. The higher virus load levels of the virus were detected in livers, spleens, and intestines, increase in virus loads in F65 and F35 at 96 h and 48 h post challenge. No mutations in E3, TNFR and ICP18 genes were observed among F5 and F65, and ICP46 had an amino acid mutation from aspartate to tyrosine, indicating that the stabilities of LMBV were observed during its successive passages. The mutation in ICP46 was hypothesized to be involved in the minimal virulence of F65. The findings were beneficial to verify the pathogenesis of LMBV and the application of its vaccine.
王丛旭, 潘晓艺, 周可欣, 穆雪娇, 姚嘉赟, 蔺凌云, 赵建华, 沈锦玉. 体外传代对大口黑鲈蛙虹彩病毒毒株毒力的影响[J]. 大连海洋大学学报, 2023, 38(4): 623-629.
WANG Congxu, PAN Xiaoyi, ZHOU Kexin, MU Xuejiao, YAO Jiayun, LIN Lingyun, ZHAO Jianhua, SHEN Jinyu. Effect of in vitro passage on virulence of largemouth bass (Micropterus salmoides) ranavirus. Journal of Dalian Ocean University, 2023, 38(4): 623-629.
2023, Vol. 38 
