Recombinant Gonadotropins to Induce Oocyte Development In Vitro and In Vivo in the European Eel Anguilla anguilla

Commonly, female European eels are injected weekly with pituitary extract (PE) from carp (CPE) or salmon (SPE) to induce sexual maturation. However, a PE is mixture of gonadotropins and other hormones that not specific for eel rapidly cleared circulation. The aim this study was therefore test the effects highly stable eel-specific recombinant (rGTHs) on oocyte development in vitro vivo eels. For trial, dose–effect responses maturing oocytes CPE luteinizing hormone (rLH) were studied before after 12 18 h incubation. experiment, maturation stimulated by treatment (i) CPE, (ii) follicle-stimulating (rFSH) followed (iii) rFSH rLH. expression nuclear progestin receptor 2 (pgr2) induced rLH, implying rLH preparing ovulation. females treated rGTHs had high gonadosomatic index (GSI) values (rFSH-CPE: 75, 77; rFSH-rLH: 80) comparison (50–60), suggesting strongly vitellogenic growth. Larvae produced all groups first time rGTH alone but dose timing still need optimization.