Fig. 6

Immunofluorescence results in duck spleens. The virus was detected in spleen between 2 hpi to 18 dpi and dispersedly distributed as dot-like particles (→), not detected at 1 hpi and 24 dpi. At 2hpi, the particles are found in the sheathed capillary (red dotted borders in Fig. 6f) and the periphery of white pulp (white dotted borders). Between 6hpi to 6dpi, the virus particles were mostly distributed in the periphery of white pulp (white dotted borders). Some virus particles are also found on the wall of the trabecular artery vessel and in the periphery of the trabecular artery (white dotted borders in Fig. 6n and p) at 3dpi and 6pi. Between 9dpi to 18dpi, the virus particles are mainly observed in the red pulp and periarteriolar lymphatic sheaths (PALS) around the central artery. Bar = 50 μm. RP: red pulp, WP: white pulp, TA: trabecular artery, CA: central artery, PALS: periarteriolar lymphatic sheaths