Zebrafish: A Versatile Animal Model for Fertility Research

Figure 1

Crosstalk between HPG and HPT in mammals. T3 displays its estrogenic action by stimulating the expression of both estrogen receptors α and β. Increased in expression of steroidogenic acute regulatory protein (StAR) followed by elevated testosterone level were also observed following acute exposure to T3. Meanwhile, administration of T4 has been shown to cause elevation in the level of LH and FSH. However, low serum testosterone was observed under T4-induced hyperthyroidism and the low testosterone level is attributed to the decreased catalytic activities of testicular enzymes involved in lipogenesis (blue arrow: HPG; pink arrow: HPT).