DOI QR코드

DOI QR Code

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

Abstract

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.

Keywords

GnRH-I;POMC;NPY;Leptin;IGF-1;Sexual Maturity;Duck

References

  1. Barash, I. A., C. C. Cheung, D. S. Weigle, H. Ren, E. B. Kabigting, J. L. Kuijper, D. K. Clifton and R. A. Steiner. 1996. Leptin is a metabolic signal to the reproductive system. Endocrinology 137:3144-3147. https://doi.org/10.1210/en.137.7.3144
  2. Barb, C. R., G. J. Hausman and K. Czaja. 2005. Leptin: a metabolic signal affecting central regulation of reproduction in the pig. Domest. Anim. Endocrinol. 29:186-192. https://doi.org/10.1016/j.domaniend.2005.02.024
  3. Blomqvist, A. G., C. Soderberg, I. Lundell, R. J. Milner and D. Larhammar. 1992. Strong evolutionary conservation of neuropeptide Y: sequences of chicken, goldfish, and Torpedo marmorata DNA clones. Proc. Natl. Acad. Sci. USA. 89:2350-2354. https://doi.org/10.1073/pnas.89.6.2350
  4. Chehab, F. F., K. Mounzih, R. Lu and M. E. Lim. 1997. Early onset of reproductive function in normal female mice treated with leptin. Science 275:88-90. https://doi.org/10.1126/science.275.5296.88
  5. Daftary, S. S. and A. C. Gore. 2003. Developmental changes in hypothalamic insulin-like growth factor-1: relationship to gonadotropin-releasing hormone neurons. Endocrinology 144:2034-2045. https://doi.org/10.1210/en.2002-221025
  6. Daftary, S. S. and A. C. Gore. 2005. IGF-1 in the brain as a regulator of reproductive neuroendocrine function. Exp. Biol. Med. 230:292-306.
  7. Ebling, F. J. 2005. The neuroendocrine timing of puberty. Reproduction 129:675-683. https://doi.org/10.1530/rep.1.00367
  8. El, M. M., A. Sahu, S. Ramaswamy and T. M. Plant. 2000. Neuropeptide Y: A hypothalamic brake restraining the onset of puberty in primates. Proc. Natl. Acad. Sci. USA. 97:6179-6184. https://doi.org/10.1073/pnas.090099697
  9. Fraley, G. S. and W. J. Kuenzel. 1993. Precocious puberty in chicks (Gallus domesticus) induced by central injections of neuropeptide Y. Life. Sci. 52:1649-1656. https://doi.org/10.1016/0024-3205(93)90047-7
  10. Genazzani, A. R., F. Bernardi, P. Monteleone, S. Luisi and M. Luisi. 2000. Neuropeptides, neurotransmitters, neurosteroids, and the onset of puberty. Ann. N.Y. Acad. Sci. 900:1-9.
  11. Gruenewald, D. A. and A. M. Matsumoto. 1991. Age-related decrease in proopiomelanocortin gene expression in the arcuate nucleus of the male rat brain. Neurobiol. Aging 12:113-121. https://doi.org/10.1016/0197-4580(91)90049-P
  12. Hu, Y., Y. D. Ni, L. Z. Ren, J. Dai and R. Q. Zhao. 2008. Leptin is involved in the effects of cysteamine on egg laying of hens, characteristics of eggs, and posthatch growth of broiler offspring. Poult. Sci. 87(9):1810-1817. https://doi.org/10.3382/ps.2008-00040
  13. Kalra, P. S. and S. P. Kalra. 1986. Steroidal modulation of the regulatory neuropeptides: luteinizing hormone releasing hormone, neuropeptide Y and endogenous opioid peptides. J. Steroid Biochem. 25:733-740. https://doi.org/10.1016/0022-4731(86)90302-X
  14. Knight, P. G. 1983. Variations in hypothalamic luteinizing hormone releasing hormone content and release in vitro and plasma concentrations of luteinizing hormone and testosterone in developing cockerels. J. Endocrinol. 99:311-319. https://doi.org/10.1677/joe.0.0990311
  15. Knight, P. G. and R. T. Gladwell and F. J. Cunningham. 1985. Release of LHRH in vitro and anterior pituitary responsiveness to LHRH in vivo during sexual maturation in pullets (Gallus domesticus). J. Reprod. Fertil. 74:145-151. https://doi.org/10.1530/jrf.0.0740145
  16. Knight, P. G., S. C. Stansfield and F. J. Cunningham. 1990. Attenuation by an opioid agonist of the oestradiol-induced LH surge in anoestrous ewes and its reversal by naloxone. Domest. Anim. Endocrinol. 7:165-172. https://doi.org/10.1016/0739-7240(90)90022-R
  17. Minami, S., S. A. Frautschy, P. M. Plotsky, S. W. Sutton and D. K. Sarkar. 1990. Facilitatory role of neuropeptide Y on the onset of puberty: effect of immunoneutralization of neuropeptide Y on the release of luteinizing hormone and luteinizinghormone- releasing hormone. Neuroendocrinology 52:112-115. https://doi.org/10.1159/000125548
  18. Prasad, B. M., C. D. Conover, D. K. Sarkar, J. Rabii and J. P. Advis. 1993. Feed restriction in prepubertal lambs: effect on puberty onset and on in vivo release of luteinizing-hormonereleasing hormone, neuropeptide Y and beta-endorphin from the posterior-lateral median eminence. Neuroendocrinology 57:1171-1181. https://doi.org/10.1159/000126484
  19. Sharp, P. J., R. T. Talbot, G. M. Main, I. C. Dunn, H. M. Fraser and N. S. Huskisson. 1990. Physiological roles of chicken LHRH-I and -II in the control of gonadotrophin release in the domestic chicken. J. Endocrinol. 124:291-299. https://doi.org/10.1677/joe.0.1240291
  20. Stansfield, S. C. and F. J. Cunningham. 1987. Modulation by endogenous opioid peptides of the secretion of LHRH from cockerel (Gallus domesticus) mediobasal hypothalamic tissue. J. Endocrinol. 114:103-110. https://doi.org/10.1677/joe.0.1140103
  21. Stevenson, T. J., and S. A. dougall-Shackleton. 2005. Season- and age-related variation in neural cGnRH-I and cGnRH-II immunoreactivity in house sparrows (Passer domesticus). Gen. Comp. Endocrinol. 143:33-39. https://doi.org/10.1016/j.ygcen.2005.02.019