Dulbecco's modified Eagle's medium (DMEM), fetal bovine serum (FBS), L-glutamine, and penicillin/streptomycin were purchased from Gibco BRL Life Technologies (Grand Island, NY, USA). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), phalloidin tetramethylrhodamine B isothiocyanate, bovine serum albumin (BSA) and dimethylsulfoxide (DMSO) were obtained from Sigma (St. Louis, MO, USA). Primary antibodies specific to Cdc42, Rac1, and RhoA were obtained from Abcam (Cambridge, UK), while the primary antibodies against β-actin, the secondary antibody goat anti-rabbit IgG/HRP, and propidium iodide (PI) were purchased from Cell Signaling Technology (Danvers, MA, USA). All other reagents used in the experiments were high-grade, commercially available products. ASX was isolated from L. vannamei as described previously [15 (link)22 ]. The extraction yield was 20.39 ± 1.02 mg of ASX per gram of shrimp shell, and identification of ASX was previously reported [15 (link)22 23 ]. ASX was dissolved in DMSO and applied to cultures at final concentrations of 0.25-1 µg/mL. The final concentration of DMSO in the culture medium was always less than 0.1% (v/v), which was non-toxic to the cell cultures.