Mycoplasma synoviae (MS) is an important pathogen that can cause respiratory diseases in poultry and birds, leading to serious economic losses in the world and impacting the development of the poultry industry. However, the pathogenic mechanisms of MS infection are still unclear, resulting in a lack of effective diagnosis and treatment strategies. This study aimed to uncover the infection effect caused by MS in chicken oviduct cells. MS-infected chicken oviduct cells with different infection times and doses were collected, and DAPI staining was performed to monitor the morphological changes of cell nuclei. Cell viability was detect by CCK-8 assay. The expression of marker genes of cell apoptosis was determined by RT-qPCR and Western blotting assay, respectively. The results showed that MS infection significantly inhibited the growth of chicken oviduct cells, caused the nuclear shrinkage and rupture, activated the expression of apoptosis marker genes Caspase 3 and Beclin-1, and increased the apoptosis rate. These results indicated that MS infection inhibits cell proliferation and promotes apoptosis in chicken oviduct cells, which provided a basis for further revealing the MS pathogenic mechanism and provided a foundation for the future development of anti-infection strategies.

The ultrastructure of submandibular gland (SMG) of Bactrian camels was observed by a transmission electron microscope. Routine HE staining, special staining combined with immunohistochemistry, and immunofluorescence techniques were used to study the histochemical characteristics of the submandibular gland and the localisation and distribution characteristics of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR). HE results showed that the submandibular gland of Bactrian camels was composed of mixed serous and mucinous acini glands. The submandibular striated duct was highly developed and connected with intercalated ducts with larger diameter. Intercalated ducts are shorter and directly connected to acini. In AB-PAS staining, it was observed that the inner wall of striated tube was strongly positive for AB staining. The distribution of the reticular fibres around the follicles and ducts of the submandibular gland is distinct, with collagen fibres distributed mainly in the periphery of the ducts and sparse collagen fibres in the periphery of the acini. Immunohistochemistry and fluorescence show that EGF is strongly positive in striated and intercalated ducts, and EGFR is weakly positive in striated and intercalated ducts. Bactrian camel SMGs secrete more acidic mucins, and EGF and EGFR were mainly secreted and play a role in the pipeline system of SMGs.