FIG. 3.

Histopathology of lung tissue at day 4 postinoculation and cDNA microarrays of selected genes relevant to neutrophil and monocyte-macrophage function. The left slide shows uninfected lungs from the control animal; the right slide shows the lungs of the infected animal at day 4 postinoculation, showing pneumonia with mild alveolar septal and luminal infiltration of lymphocytes, neutrophils (black arrows), eosinophils, and macrophages (blue arrows), hypertrophy (red arrow), and hyperplasia (mitotic figures) in many pneumocytes with dark basophilic nuclei and cytoplasm but little or no apparent transudation to the alveoli. Magnification, ×70. The genes in these biosets were extracted from the cluster in appendix A, i.e., they were differentially regulated by 1.5-fold or more in at least two experiments (P ≤ 0.05) and were clustered according to a hierarchical algorithm. Red bars represent genes that were induced by the experiment; green bars represent genes that were repressed by the experiment; and darker colors represent lesser differential expression. The genes in the heat maps whose border color corresponds to a label on the histology slides are highly relevant to but not necessarily exclusive to the function of the labeled cells.