FIG 2.

Nasal mucosa. Domestic 2- and 15-week-old pig were intranasally inoculated with the NIA3 strain and euthanized at different time points postinfection. mRNA expression of several PRV genes in the nasal mucosa was studied by RT-qPCR in 2- and 15-week-old pigs (a and d, respectively). Viral gene levels were expressed relative to the lowest positive sample for each age category. Furthermore, cytokine-related mRNA expression in de nasal mucosa was tested by RT-qPCR in 2- and 15-week-old pigs (panels b and c and panels e and f, respectively). Individual cytokine levels for all animals are expressed relative to the average cytokine expression in the control group (separately for 2- and 15-week-old animals).