Changes of Hypothalamic GnRH-I, POMC and NPY mRNA Expression and Serum IGF-I and Leptin Concentrations during Maturation of Shaoxing Ducks (Anas platyrhynchos)

  • Ni, Y. (Key Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University) ;
  • Lu, L. (Institute of Animal Science, Zhejiang Academy of Agriculture Sciences) ;
  • Chen, J. (Key Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University) ;
  • Zhao, Ruqian (Key Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University)
  • Received : 2011.01.29
  • Accepted : 2011.05.10
  • Published : 2011.09.01


Sexual maturity in poultry is controlled by a complex neural circuit located in the basal forebrain, which integrates the central and peripheral signals to activate hypothalamic gonadotrophin-releasing hormone (GnRH) secretion. This study demonstrated the changes of GnRH-I, POMC and NPY mRNA transcription in hypothalamus and IGF-I and leptin levels in serum of Shaoxing ducks during puberty. Body weight increased progressively from d30 to d120 and at d120 the flock reached 5% of laying rate. A significant upregulation of hypothalamic GnRH-I mRNA expression was observed from d60, reaching the peak at d120. POMC and NPY mRNA expression in hypothalamus showed a similar pattern, which increased from d30 to d60, followed by a significant decrease towards sexual maturity. Serum IGF-I levels exhibited two peaks at d30 and d120, respectively. Serum leptin displayed a single peak at d90. The results indicate that the down-regulation of POMC and NPY genes in hypothalamus coincides with the up-regulation of GnRH-I gene to initiate sexual maturation in ducks. In addition, peripheral IGF-I and leptin may relay the peripheral metabolic status to the central system and contribute to the initiation of the reproductive function in ducks.


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