FIG 10.

Comparison of the growth curves of BeauR-M41(S), BeauR-M41(S1), and BeauR-M41(S2). Multistep growth curves in CK cells derived from Valo chickens (A), 24-h growth curves (B), and single-step, 12-h growth curves (C) in CK cells derived from RIR chickens are depicted. Supernatant was harvested at various time points postinfection, and titers of progeny virus were determined by a plaque titration assay on CK cells. Data points represent the means of three independent experiments, and error bars represent the SEM.