Abstract:
A 10-week feeding experiment in indoor flowing-through water system was conducted to evaluate the effects of taurine, methionine and cysteine in diets on growth performance and taurine transporter (
TauT) mRNA expression of juvenile turbot (
Scophthalmus maximus L.)initial weight:(7.90±0.07) g. The basal diet was supplemented with 0, 1%, 2% taurine, 0.5% methionine and 0.5% cysteine (Control T-0, T-1, T-2, M-0.5 and C-0.5, respectively) to formulate five isonitrogenous and isolipidic diets. The results showed that the specific growth rate (
SGR) and feed efficiency (
FE) of T-1 and T-2 group were significantly higher than that of the control group (
P < 0.05), and the visceral indexes (
VSI) of T-1 and T-2 group was significantly lower than that of the control group (
P < 0.05). Compared with T-0 group, the
SGR and
FE of M-0.5 group improved (
P>0.05), and
VSI decreased significantly (
P < 0.05), while condition factors (
CF) increased significantly (
P < 0.05). Compared with T-0 group, the
SGR of C-0.5 group decreased signifi-cantly (
P < 0.05), and no significant differences in
FE,
VSI and
CF were observed (
P>0.05) between the two groups. T-1 and T-2 group had significantly lower
TauT mRNA relative expression (
P < 0.05) in liver, brain and eye tissues than those in T-0 group, and the
TauT mRNA relative expression in liver, brain and eye tissues decreased significantly (
P < 0.05) with increasing dietary taurine level. On the contrary, the
TauT mRNA relative expression in liver, brain and eye tissues of M-0.5 group was significantly higher (
P < 0.05) than those in T-0, T-1 and T-2 groups. C-0.5 group had a significantly higher
TauT mRNA relative expression (
P < 0.05) in liver, brain and eye than those in T-0, T-1 and T-2 groups, but no significant differences (
P>0.05) were found when compared with M-0.5 group. In conclusion, 0.48%, 1.06% taurine in diets could promote growth performance of juvenile turbot under these experimental conditions. The
TauT mRNA expression in juvenile turbot may be affected by dietary sulfur-containing amino acids such as taurine, methionine and cysteine.