Effects of recombinant gonadotropin hormones on the gonadal maturation in the spotted scat, Scatophagus argus

Gonadotropins (GtHs) are crucial regulators of reproductive endocrinology in teleosts. In the present study, the full cDNA sequences of FSH and LH in the spotted scat (Scatophagus argus) were cloned, and recombinant FSH (r-SaFSH) and LH (r-SaLH) proteins were obtained via prokaryotic expression. Meanwhile, we investigated the effects of recombinant GtHs on the reproductive function in the spotted scat. The plasma concentration of steroid hormone E2 in females and that of 11-kT in males were significantly increased (p < 0.01) after injection of r-SaFSH and r-SaLH. mRNA expression levels of Star, SaGtH, and 17β-hsd were elevated, but Amh expression was decreased no matter in males or females after the injection. Histological observations via SEM and H&E staining showed that gonadal development was accelerated following the treatment with r-SaFSH and r-SaLH. These results indicate that recombinant LH and FSH can activate sexual steroid signaling and regulate expression of SaGtHR, Amh, Star and 17β-hsd. Feeding with r-SaFSH and r-SaLH could also advance gonadal maturation in S. argus. The recombinant GtHs can be utilized in the artificial induction of gonadal maturation in spotted scat and other teleosts.