Figure 1.
Quality assessment of gene data and differential gene expression screening.
A: A box plot was used to compare the distributions of the intensities from all samples. The distributions of log2 ratios among samples are nearly the same; B: A scatter plot was used to assess gene expression variation (or reproducibility) between the two groups. The genes above the top green line and below the bottom green line indicate a >2.0-fold change in expression between the two groups; C: Volcano Plots were used to visualize differential expression between the two groups. The vertical lines correspond to 2.0-fold increase and decrease, whereas the horizontal line represents a p-value of 0.05. The red dot in the plot represents differentially expressed genes with statistical significance. “S2308” refers to the groups of free-living bacteria in TSB, “C2308” refers to the groups of intracellular bacteria.
Figure 2.
Heat map and hierarchical clustering.
Hierarchical clustering was performed based on all differentially expressed gene data. The results of hierarchical clustering on conditions show distinguishable gene expression profiling between samples. “Red” indicates high relative expression, and “blue” indicates low relative expression. “S2308” refers to the groups of free-living bacteria in TSB, “C2308” refers to the groups of intracellular bacteria.
Figure 3.
Significant pathway of differentially expressed genes.
“P value” indicates the enrichment p-value of the Pathway ID determined by the Fisher's exact test. “Enrichment_Score” indicates the enrichment score value of the Pathway ID, which equals -log10 (p-value). A: Significant pathways of up-regulated genes; B: Significant pathway of down-regulated genes.
Table 1.
Intracellular transcriptional level of Brucella genes obtained by qRT-PCR and analysis of gene functional characteristics.
Figure 4.
RAW264.7 cells were infected with Δddp mutant or wild type strain 2308 at a MOI 100∶1. A: The CFUs of total bacteria adherence to RAW264.7 cells. B: The CFUs of total bacteria invasion of RAW264.7 cells. C: Bacterial survival in RAW264.7 cells at 1 h, 12 h, 24 h, 36 h and 48 h p.i. All data are expressed as mean ± standard deviation and subjected to Student’s t-test, **, p≤0.01.