Pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) play central roles in regulating gametogenesis and the production of gonadal hormones, in fish as in other vertebrates. Pituitary gonadotropins are composed of two non-covalently associated polypeptide subunits, which must be glycosylated, folded, and assembled as a heterodimer to be biologically active. Since biotechnology for the production of recombinant proteins has been greatly advanced, it is possible that fish FSH and LH are produced biotechnologically as an alternative way for various manipulations in modern aquaculture. This review discusses different platforms currently being applied for recombinant piscine gonadotropin production. | Fish recombinant gonadotropins by Berta LEVAVI-SIVAN 1 Matan GOLAN 1 Joseph AIZEN 1 Abigail ELIZUR 2 ABSTRACT. - Pituitary gonadotropins follicle-stimulating hormone FSH and luteinizing hormone LH play central roles in regulating gametogenesis and the production of gonadal hormones in fish as in other vertebrates. Pituitary gonadotropins are composed of two non-covalently associated polypeptide subunits which must be glycosylated folded and assembled as a heterodimer to be biologically active. Since biotechnology for the production of recombinant proteins has been greatly advanced it is possible that fish FSH and LH are produced biotechnologically as an alternative way for various manipulations in modern aquaculture. This review discusses different platforms currently being applied for recombinant piscine gonadotropin production. Key words. - Expression system - Yeast - Insect cells - Estradiol - Follicle - Stimulating hormone - Luteinizing hormone. Introduction It has been almost a century since the laboratories of Cushing and Aschner performed the first pituitary ablation studies implicating this gland as a primary regulator of vertebrate reproduction. The gonadotropic effects of pituitary extracts were soon associated with two distinct endocrine factors known as gonadotropins GTHs that became designated as follicle-stimulating hormone FSH and luteinizing hormone LH Campbell 2005 . Phylogenetic analyses based on the amino acid sequences of vertebrate gonadotropin subunits either derived from chemically isolated peptides or deduced from cDNAs revealed monophylogenetic lineage for each subunit. The observed common ancestral origin for piscine and tetrapod gonadotropin subunits has justified the use of the terms FSH and LH for the fish GtH I and GtH II respectively Yaron et al. 2003 . In fishes FSH is considered to regulate early phases of gametogenesis such as vitellogenesis and spermatogenesis whereas LH is responsible for the final maturation processes such as .
