(A–C) Oil red O extraction was performed for the two GC methods at three stages, (D) and two-way ANOVA was performed. The different lowercase letters (a and b) at the top of each bar represent the significant differences among lipid deposition at different time points using the same culture method and the same stages (P< 0.05), and the * represents the significant differences between culture methods at the same time points and stages (*P<0.05 and **P<0.01, respectively).