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This Article Full Text Full Text (PDF) All Versions of this Article: 79/5/938    most recent biolreprod.108.070052v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal My Folders Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kazeto, Y. Articles by Yamauchi, K. Search for Related Content PubMed PubMed Citation Articles by Kazeto, Y. Articles by Yamauchi, K. Agricola Articles by Kazeto, Y. Articles by Yamauchi, K.

Japanese Eel Follicle-Stimulating Hormone (Fsh) and Luteinizing Hormone (Lh): Production of Biologically Active Recombinant Fsh and Lh by Drosophila S2 Cells and Their Differential Actions on the Reproductive Biology¹

National Research Institute of Aquaculture,³ Fisheries Research Agency, Minami-ise 516-0193, Japan Division of Marine Life Sciences,⁴ Research Faculty of Fisheries Science, Hokkaido University, Hakodate 041-8611, Japan South Ehime Fisheries Research Center,⁵ Research Group for Reproductive Physiology, Ehime University, Ainan 798-4292, Japan Center of Marine Biotechnology,⁶ University of Maryland Biotechnology Institute, Baltimore, Maryland 21202

ABSTRACT

Two gonadotropins (Gths), follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh), control gonadal steroidogenesis and gametogenesis in vertebrates, including teleost fish. Here, we report on the production of biologically active recombinant Fsh (rec-Fsh) and Lh (rec-Lh) in Japanese eel using Drosophila S2 cells. The three subunits composing Gths, i.e., glycoprotein hormone, alpha polypeptide (Cga), follicle-stimulating hormone, beta polypeptide (Fshb), and luteinizing hormone, beta polypeptide (Lhb), were at first independently produced and were proven to be glycosylated and secreted as the mature peptides. Each beta subunit, along with its Cga, was simultaneously coexpressed to produce heterodimeric rec-Fsh and rec-Lh that were subsequently highly purified. The biological activity of rec-Gths was demonstrated in various in vitro assays. The rec-Gths differentially activated their receptors, which resulted in an increase in 11-ketotestosterone (11KT) secretion, a differential alteration of gene expression of steroidogenic enzymes in immature testis, and the induction of the complete process of spermatogenesis in vitro. The data strongly suggest that Fsh and Lh differentially play important roles in the reproductive physiology of the Japanese eel. By contrast, these rec-Gths exhibited little activity in the gonad when administered in vivo. This difference between in vitro and in vivo bioactivity is probably due to the qualitative nature of glycosylation in S2 cells, which resulted in degradation of the recombinant protein in vivo. These differences in the carbohydrate moieties need to be elucidated and ameliorated..

follicle-stimulating hormone, FSH, gametogenesis, Japanese eel, LH, luteinizing hormone, steroid hormones, steroidogenesis

¹Supported by grants from the Ministry of Agriculture, Forestry and Fisheries (MAFF) and the 21st Century COE Program "Marine Bio-Manipulation Frontier for Food Production" of the Ministry of Education, Culture, Sports, Science and Technology of Japan.

Correspondence: ²Correspondence: FAX: 81 599 66 1962; e-mail: kazeto{at}fra.affrc.go.jp