Fig. 4.

Relative expression of TOR, S6K1, 4E-BP1, and ATF4 in the PI, MI, and DI of the on-growing grass carp (Ctenopharyngodon idella) fed diets containing graded levels of VD₃ for 10 weeks. Mean values ± SD. n = 6 for each bar. Different letters above the bars indicate significant difference (ANOVA and Duncan's multiple-range test, P < 0.05). TOR = total target of rapamycin; S6K1 = S6 kinase 1; 4E-BP1 = eukaryotic translation initiation factor 4E-binding protein 1; ATF4 = activating transcription factor 4; PI = proximal intestine; MI = mid intestine; DI = distal intestine.