Pathogenicity comparison between QX-type and Mass-type infectious bronchitis virus to different segments of the oviducts in laying phase

Fig. 1. Immunohistochemistry detection of QX and Mass-type IBV antigens 4 days post infection. A1–D1 Different segments of oviduct in the control group. A2–D2 Different segments of oviduct in the QXL group. A3–D3 Different segments of oviduct in the M41 group. E The sum of IOD in different segments of oviduct. *P < 0.05, **P < 0.01, ***P < 0.001 represent significant differences between the QXL group and the M41 group. Black arrows indicate antigen deposition. Scale bars: 50 or 100 μm. E, mucosal epithelium; L, lumen; LP, lamina propria

Fig. 2. Histopathological analysis of the pathogenicity of QX and Mass-type IBV in the oviduct 4 days post infection. A1–D1 Different segments of oviduct in the control group. A2 Infundibulum of the QXL group, black arrows indicate macrophages and lymphocytes distributed in the connective tissue in the lamina propria, white arrows indicate the expansion of tubular glands. B2 Magnum of the QXL group, white arrows indicate the expansion of tubular glands. C2 Isthmus of the QXL group, black arrows indicate lymphocytes infiltrating the interstitium of the lamina propria. D2 Uterus of the QXL group, white arrows indicate interstitial dilation. C3 Isthmus of the M41 group, white arrows indicate the desquamation of epithelial cells. D3 Uterus of the M41 group, white arrows indicate the desquamation of epithelial cells. Scale bars: 50 μm. E, mucosal epithelium; L, lumen; LP, lamina propria

Fig. 3. Effects of QX and Mass-type IBV in different segments of the oviduct on mRNA expression of proinflammatory cytokine genes. A IL-6, B IL-1β, C IFN-γ and D IL-2. Values are shown as the mean ± SEM (n = 3) of fold change in expression. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 represent significant differences between the infection groups and the control group. DPI, days post infection; SEM, standard error of the mean

Fig. 4. Effects of QX and Mass-type IBV in different segments of the oviduct on mRNA expression of IFN-α (A), granzyme (B) and perforin (C). Values are shown as the mean ± SEM (n = 3) of fold change in the expression. *P < 0.05, **P < 0.01, ***P < 0.001 represent significant differences between the infection groups and the control group. DPI, days post infection; SEM, standard error of the mean

Fig. 5. Effects of QX and Mass-type IBV in the isthmus and uterus on the mRNA expression of type I collagen (A) and CaBP-D28K (B). Values are shown as the mean ± SEM (n = 3) of fold change in the expression. *P < 0.05, **P < 0.01 represent a significant difference between the infection groups and the control group. DPI, days post infection; SEM, standard error of the mean