RT Journal Article
T1 Amino acidic substitutions in the polymerase N-terminal region of a reassortant betanodavirus strain causing poor adaptation to temperature increase
A1 Souto Pereira, Sandra
A1 Vázquez Salgado, Lucía
A1 Olveira Hermida, José Gabriel
A1 Bandín Matos, Isabel
AB Nervous necrosis virus (NNV), Genus Betanodavirus, is the causative agent of viral encephalopathy and retinopathy (VER), a neuropathological disease that causes fish mortalities worldwide. The NNV genome is composed of two single-stranded RNA molecules, RNA1 and RNA2, encoding the RNA polymerase and the coat protein, respectively. Betanodaviruses are classified into four genotypes: red-spotted grouper nervous necrosis virus (RGNNV), striped jack nervous necrosis virus (SJNNV), barfin flounder nervous necrosis virus (BFNNV) and tiger puffer nervous necrosis virus (TPNNV). In Southern Europe the presence of RGNNV, SJNNV and their natural reassortants (in both RNA1/RNA2 forms: RGNNV/SJNNV and SJNNV/RGNNV) has been reported. Pathology caused by these genotypes is closely linked to water temperature and the RNA1 segment encoding amino acids 1–445 has been postulated to regulate viral adaptation to temperature. Reassortants isolated from sole (RGNNV/SJNNV) show 6 substitutions in this region when compared with the RGNNV genotype (positions 41, 48, 218, 223, 238 and 289). We have demonstrated that change of these positions to those present in the RGNNV genotype cause low and delayed replication in vitro when compared with that of the wild type strain at 25 and 30 °C. The experimental infections confirmed the impact of the mutations on viral replication because at 25 °C the viral load and the mortality were significantly lower in fish infected with the mutant than in those challenged with the non-mutated virus. It was not possible to challenge fish at 30 °C because of the scarce tolerance of sole to this temperature.
PB BMC
SN 0928-4249
YR 2019
FD 2019
LK http://hdl.handle.net/10347/21463
UL http://hdl.handle.net/10347/21463
LA eng
NO Souto, S., Vázquez-Salgado, L., Olveira, J.G. et al. Amino acidic substitutions in the polymerase N-terminal region of a reassortant betanodavirus strain causing poor adaptation to temperature increase. Vet Res 50, 50 (2019). https://doi.org/10.1186/s13567-019-0669-4
NO This work was supported by Grant AGL2014-54532-C2-2-R from the Ministerio the Innovación y Competitividad (Spain), cofunded by FEDER, and by Grant ED431C 2018/18 from Xunta de Galicia (Spain)
DS Minerva
RD 27 abr 2026