Dulbecco modified eagle medium (dmem)

Chicken HD11 and DF-1 cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM, Cellmax, Beijing, China) supplemented with 10% fetal bovine serum (FBS, Cellmax) and 100  IU/mL penicillin–streptomycin solution (Cellmax). All cells were cultured in an incubator at 37 °C in 5% CO₂.
The IBV Beaudette strain (GenBank: DQ001339) was kindly gifted by Prof. Ding-Xiang Liu, South China Agricultural University.
Mouse monoclonal antibodies specific for Flag and β-actin, rabbit polyclonal anti-Myc antibodies, CoraLite488-conjugated donkey anti-mouse IgG (H + L), CoraLite594-conjugated donkey anti-rabbit IgG (H + L), HRP-conjugated Affinipure donkey anti-mouse IgG (H + L), and HRP-conjugated Affinipure donkey anti-rabbit IgG (H + L) were purchased from Proteintech (Wuhan, China). Mouse monoclonal anti-IBV N protein antibodies were from Novus Biologicals (Littleton, CO, USA). Rabbit polyclonal anti-chJAK1 and anti-chSTAT1 antibodies were from Abmart (Shanghai, China) and Bioss (Beijing, China), respectively.

NIH/3T3 and 293T cells were cultured in DMEM (CGM101.05; CellMax, Lanzhou, China). JEG3 cells were cultured in EMEM (11700; Cary, Huzhou, China). HTR8/SVneo cells and Ishikawa cells were cultured in RPMI medium (C11875500BT; Thermo Fisher Biochemical, China). Cells were cultured at 37°C in a 5% CO₂ atmosphere, and all culture media were supplemented with 100 U/ml penicillin and streptomycin (BL505A; Biosharp, Beijing, China) and 10% foetal bovine serum (CellMax, Lanzhou, China).
KRT18 antibody was purchased from Novus Biologicals (NPB2-67370; Littleton, CO, USA). Phalloidin was purchased from Thermo Fisher Scientific (A22284; USA). KRT18 fusion protein (Ag1260) and E-cadherin fusion protein (Ag15085) were purchased from Proteintech (Wuhan, Hubei, P.R.C.).