Figure 4

Gene expression in chickens inoculated with wild-type S. Enteritidis and its mutants. Chickens were infected on day of hatch with wild-type S. Enteritidis or SPI1, SPI2, phoP and aroA mutants, and euthanized 4 days later. Heat map shows average gene expression in groups of chickens. Asterisks indicate statistically significant difference from the expression in the non-infected chickens at P ≤ 0.05 (*), P ≤ 0.01 (**), or P ≤ 0.001 (***). Maximal fold increase is shown to highlight the differences between the green and red color range for each of the genes. Minimal and maximal expression levels are shown to remind that higher fold inductions are more frequent for genes with a lower basal expression.