Effects of 17 β-estradiol on the vitellogenin synthesis and oocyte development in the ovary of kuruma prawn (Marsupenaeus japonicus)

The effects of 17 β-estradiol on induction of vitellogenin synthesis and oocyte development were investigated in previtellogenic ovary of immature kuruma prawn (Marsupenaeus japonicus) incubated with Medium 199. After three days incubation of previtellogenic ovary, Vg concentrations in media containing 3.6 nM, 36.7 nM, 367 nm and 3671 nM 17 β-estradiol were significantly (p < 0.01) greater than that of Ringer solution or the pure ethanol vehicle. Furthermore, a more advanced stage of oocyte development at oil globule stage (primary vitellogenic stage), which is surrounded by round and greatly expanded follicle cells, was observed in previtellogenic ovarian pieces incubated in media containing 3.6, 36.7, 367 and 3671 nM 17 β-estradiol. The results of these studies show that 17 β-estradiol induces Vg synthesis and appearance of primary vitellogenic oocyte in the ovary of immature prawns.