Fig. 4

Effect of cysteine (a-f) or L-serine (g-l) on CS, GDH and SPAT gene expression in A. castellanii trophozoites. a-c Gene expression levels after treatment with different concentrations of cysteine (10, 20 and 40 mM) for 12 h. d-f Gene expression levels after treatment with cysteine for 24 h. g-i Gene expression levels after treatment with different concentrations of L-serine (10, 20 and 40 mM) for 12 h. j-l Gene expression levels after treatment with serine for 24 h. As a control, trophozoites were cultured in PYG medium with no amino acid treatment. Vertical bars indicate SD. *P < 0.05, **P < 0.01 and ***P < 0.001 by one-way ANOVA