Prostaglandin affects in vitro ovulation and 17α, 20β-Dihydroxy- 4-pregnen-3-one production in longchin goby, Chasmichthys dolichognathus oocytes

This study focused on the association of prostaglandins and a progestin, 17α, 20β-dihydroxy-4-pregnen-3-one (17α20βP) during the ovulation process in longchin goby, Chasmichthys dolichognathus. We performed several in vitro experiments using 850–920 μm diameter oocytes which were at the migratory nucleus stage. With the 890–920 μm diameter oocytes, no significant difference in ovulation was observed in any of the prostaglandins (PGE1, PGE2, and PGF2α) treated groups although PGE2 and PGF2α at concentrations of 50 ng/mL increased ovulation slightly compared with controls; however, 17α20βP production was stimulated with PGE1 alone at low concentrations (5 ng/mL). In 850 μm diameter oocytes, PGF2α at concentrations of 50 and 500 ng/ml resulted in a significant increase in ovulation. 17α20βP (50 ng/ml) alone had no observable effect on ovulation, but in the combined of PGF2α 50 or 500 ng/ml it caused the greatest effect on ovulation. The sensitivity of oocytes to the induction of ovulation varies between 850 and 890–920 μm, it appeared to vary depending on the migration status of nucleus. These results suggest that PGF2α (or combined of 17α20βP) was more potent in inducing ovulation of the longchin goby.