Bioluminescence and weight loss in directly inoculated mice.

129X1 mice were inoculated intranasally with 70- (A) or 7,000- (B) PFU of rSeV-luc(M-F*), or PBS (C) and bioluminescence in the nasopharynx (red triangles), trachea (orange circles), and lungs (blue squares) was measured for 14 days. Seventy days after the initial inoculation, the same mice were challenge with a lethal dose of 3×10⁶-PFU of rSeV-luc(M-F*) and bioluminescence was again measured daily. (D) Weight loss was used as a measure of morbidity and was monitored throughout the course of experiment. All numbers are reported as the means ± the standard deviation (70-PFU n = 22 and 7,000-PFU n = 48). The bottom of the y-axis is 5.5×10⁵ photons/s, the limit of detection of bioluminescence.