Journal: Virulence

Article Title: Identification of fidelity-determined residues of Porcine reproductive and respiratory syndrome virus through structural alignment

doi: 10.1080/21505594.2026.2629134

Figure Lengend Snippet: Resistance of PRRSV nsp9-RdRp mutant viruses to nucleoside analog mutagens . (A) Identification of the nsp9 mutant viruses by IFA in MARC-145 cells at 48 hours post inoculation(hpi). (B) The multistep growth analysis of mutant strains. At the indicated time points, the infected cells were harvested and subjected to titration by TCID 50 assay. (C and D) resistance of PRRSV nsp9 mutant viruses to ribavirin(orange), 5-FU(blue) and 5-AZC(purple). MARC-145 cells were infected at MOI of 0.01, and infection proceeded for 24 hours(C) or 48 hours(D). The virus titers were determined by TCID 50 assay. (E and F) The virus titer difference between with or without analog treatment at 24 hpi(E) or 48 hpi(F). The nucleoside analog resistance data are from three independent experiments, with error bars representing standard error of the mean (SEM). Statistical significance is indicated as * p < 0.05, ** p < 0.01, *** p < 0.001.

Article Snippet: The MARC-145 cell line(ATCC, CRL-12231), derived from the African monkey kidney MA-104 cell line, was cultured in Dulbecco’s modified Eagle’s medium(DMEM; Gibco, 12,491,015) supplemented with 10% fetal bovine serum(FBS; Gibco, 16,140,071), 50 U/mL penicillin, and 50 μg/mL streptomycin, at 37°C in a humidified 5% CO 2 atmosphere.

Techniques: Mutagenesis, Infection, Titration, Virus

Journal: Virulence

Article Title: Identification of fidelity-determined residues of Porcine reproductive and respiratory syndrome virus through structural alignment

doi: 10.1080/21505594.2026.2629134

Figure Lengend Snippet: Resistance of PRRSV nsp9 K336 and K541 mutant viruses to nucleoside analog mutagens. (A) The spatial positions of K336 and K541 in the PRRSV RdRp domain are highlighted with arrows. Both lysines are located within the RNA channel and near the SDD active site. (B) Amino acid sequence alignments indicate that K336 is conserved across PRRSV-2 strains. (C) IFA identification of PRRSV N protein in MARC-145 cells at 48 hpi. (D) The growth kinetics of the K336 and K541 mutant strains. (E and F) The titer of PRRSV nsp9 K541/K336 mutant viruses with or without ribavirin, 5-FU or 5-AZC treatment. Each treatment was colored as mentioned above. MARC-145 cells were infected at MOI of 0.01, and infection proceeded for 24 hours(E) or 48 hours(F). The virus titers were determined by TCID 50 assay. (G and H)The viruses titer difference between with or without nucleoside analog treatment at 24 hpi(G) or 48 hpi(H). Data reflect results from three independent experiments, with error bars indicating SEM and statistical significance is noted(* p < 0.05, ** p < 0.01, *** p < 0.001).

Article Snippet: The MARC-145 cell line(ATCC, CRL-12231), derived from the African monkey kidney MA-104 cell line, was cultured in Dulbecco’s modified Eagle’s medium(DMEM; Gibco, 12,491,015) supplemented with 10% fetal bovine serum(FBS; Gibco, 16,140,071), 50 U/mL penicillin, and 50 μg/mL streptomycin, at 37°C in a humidified 5% CO 2 atmosphere.

Techniques: Mutagenesis, Sequencing, Infection, Virus