Document Type : Research Paper
P450 aromatase (CYP19(a)) is the key steroidogenic enzyme responsible for conversion of androgens to estrogens which play a critical role in developmental and sex differentiation. Hence, this study was done to evaluate the effect of Vitex agnus castus hydroalchoholic extract on reproductive performance, sex ratio and expression of CYP19(a), one of the most important gene related to gender, using RT-PCR method in zebrafish. The larvae were fed post-hatching with diets containing extracts of four levels included 0 (control group T0), 5 (T1), 10 (T2) and 15 (T3) g/Kg food for 45 days. For gene expression studies, samples of larvae at 4, 7, 10, 15, 30 and 45 days post-hatching were collected. Expression of β-actin housekeeping genes was normalized as reference gene. Gene expression was evaluated by using 2-ΔΔCT method. The reproductive performance was significantly better in T2 and T3 than other treatments (P<0.05). With increasing concentration of extract in the diet, the ratio of female to male increased (P<0.05). T3 Treatment leading to 87.23% female. The use of plant extract increased the expression of gene CYP19(a), so at the time of differentiation of gonad (45 days after hatching), the highest expression of this gene was occurred. Overall, suggest the use of T3 treatment to achieve the best reproductive performance and a higher percentage of females in zebrafish as model for aquaculture species.