Reduced Concentration of Androstenone and Up-Regulation of 3β-Hydroxysteroid Dehydrogenase and 17β-Hydroxysteroid Dehydrogenase mRNA Levels by Active Immunisation Against Gonadotropin Releasing Hormone I

Abstract

The aim of this study was to investigate the efficacy of active immunisation against recombinant maltose binding protein-gonadotropin releasing hormone I (MBP-GnRH-I6) in preventing boar taint. The concentrations of testosterone and anti-GnRH-I antibodies in serum were determined by radioimmunoassay and enzyme linked immunosorbent assay, respectively. The mRNA levels of 3 -hydroxysteroid dehydrogenase (3 -HSD) and 17 -hydroxysteroid dehydrogenase (17 -HSD) in testes were analysed by real time quantitative PCR. The concentrations of androstenone and 3-methylindole in backfat were assayed by HPLC. Active immunisation against MBP-GnRH-I6 increased the serum concentration of anti-GnRH-I antibodies (P<0.05) and the levels of 3 -HSD and 17 -HSD mRNA in testis. However, it reduced the serum concentrations of testosterone (P<0.05) and androstenone. The concentration of 3-methylindole in backfat (P>0.05) was not changed. Thus, we conclude that vaccination against MBPGnRH-I6 is a practical and effective method to suppress the synthesis of androstenone.