Sexual maturation in hens is not associated with increases in serum leptin and the expression of leptin receptor mRNA in hypothalamus

Journal of Animal Science and Biotechnology

Ruqian Zhao²  Shaoqing Wang²  Jinfang Lv¹  Yingdong Ni² 

[1] Animal Science College, Anhui Science and Technology University, Fengyang 233100, P. R. China;Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, P. R. China

关键词: Sexual maturation;    Leptin;    Hypothalamus;    Hens;    Gonadatrophin Releasing hormone (GnRH);   

Others  :  805431
DOI  :  10.1186/2049-1891-4-24

 received in 2012-03-28, accepted in 2013-06-13,  发布年份 2013

【 摘 要 】

Background

In mammals, leptin is an attractive candidate for mediating the metabolic signal and the reproductive function via the specific receptor in hypothalamus. However, till now, the role of leptin on reproduction in birds is less well established. This experiment was conducted to elucidate the role of leptin on the onset of reproduction in bird, as a first step, to detect the changes of peripheral leptin and leptin receptor mRNA expression in hypothalamus between mature and immature hens at the same age. 120 ISA brown pullets at D60 were allocated randomly into two groups, long light (LL) group being raised under artificial light regimes with incrementally increased light phase (from 8 L:16D to 14 L:12D) and short light (SL) group raised on consistent light (8 L:16D) for 12 wk.

Results

The results showed that pullets in LL group reached sexual maturation 15 d earlier than those in SL group. Serum E₂ showed a significant increase with age, but no difference was observed between two groups. Serum leptin concentration decreased significantly from D112 to D136 in LL, and was markedly higher in LL group than that in SL at D112, while there was no significant difference between two groups at D136. Leptin receptor and GnRH-I mRNA expression in hypothalamus were significantly increased with age, yet there was no significant difference between SL and LL chickens at the same age. The expression of FSH-β and LH-β mRNA in pituitary was increased with age but did not show significant difference between LL and SL group. GnRH-I mRNA expression was very rich in pineal gland, and decreased from D112 to D136 in LL but not in SL group, and there was no difference between two groups at the same age.

Conclusions

These results indicate that the earlier sexual maturation in hens induced by long-light regime is not accompanied with an increase in serum leptin or leptin receptor gene expression in hypothalamus, or genes expression in HPG axis.

【 授权许可】

   
2013 Ni et al.; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Frisch RE, McArthur JW: Menstrual cycles: fatness as a determinant of minimum weight for height necessary for their maintenance or onset. Science 1974, 185:949-951.
• [2]Zhang Y, Proenca R, Mafei M, Maffei M, Barone M, Leopold L, Friedman JM: Positional cloning of the mouse obese gene and its human homologue. Nature 1994, 372:425-431.
• [3]Bourguignon JP, Rasier G, Lebrethon MC, Gérard A, Naveau E, Parent AS: Neuroendocrine disruption of pubertal timing and interactions between homeostasis of reproduction and energy balance. Mol Cell Endocrinol 2010, 324:110-120.
• [4]Barash IA, Cheung CC, Weigle DS, Ren HP, Kabigting EB, Kuijper JL, Clifton DK, Steiner RA: Leptin is a metabolic signal to the reproductive system. Endocrinology 1996, 137:3144-3147.
• [5]Barb CR, Yan X, Azain MJ, Kraeling RR, Rampacek GB, Ramsay TG: Recombinant porcine leptin reduces feed intake and stimulates growth hormone secretion in swine. Domest Anim Endocrinol 1998, 15:77-86.
• [6]Chehab FF, Lim ME, Ronghue L: Correction of the sterility defect in homozygous obese female mice by treatment with the human recombinant leptin. Nat Genet 1996, 12:318-320.
• [7]Mounzih K, Lu R, Chehab FF: Leptin treatment rescues the sterility of genetically obese ob/ob males. Endocrinology 1997, 138:1190-1193.
• [8]Paczoska-Eliasiewicz HE, Proszkowiec-Weglarz M, Proudman J, Jacek T, Mika M, Sechman A, Rzasa J, Gertler A: Exogenous leptin advances puberty in domestic hen. Domest Anim Endocrinol 2006, 31:211-226.
• [9]Foster DL, Nagatani S: Physiological perspectives on leptin as a regulator of reprodution: role in timing puberty. Biol Reprod 1999, 60:205-215.
• [10]Chehab FF, Mounzih K, Lu R, Lim ME: Early onset of reproductive function in normal female mice treated with leptin. Science 1997, 275:88-90.
• [11]Garcia MR, Amstalden M, Williams SW, Stanko RL, Morrison CD, Keisler DH, Nizielski SE, Williams GL: Serum leptin and its adipose gene expression during pubertal development, the estrous cycle, and different seasons in cattle. J Anim Sci 2002, 80:2158-2167.
• [12]Barb CR, Hausman GJ, Czaja K: Leptin: a metabolic signal affecting central regulation of reproduction in the pig. Domest Anim Endocrinol 2005, 29:186-192.
• [13]Hu Y, Ni YD, Ren LZ, Dai J, Zhao RQ: Leptin is involved in the effects of cysteamine on egg laying of hens, characteristics of eggs, and posthatch growth of broiler offspring. Poult Sci 2008, 87(9):1810-1817.
• [14]Bronson FH: Puberty in female mice is not associated with increases in either body fat or leptin. Endocrinology 2001, 142:4758-4761.
• [15]Siopes TD, Millam JR, Steinman MQ: Initiating egg production in turkey breeder hens: thyroid hormone involvement. Poult Sci 2010, 89(10):2265-2272.
• [16]Zhang XY, Zhang Q, Wang DH: Litter size variation in hypothalamic gene expression determines adult metabolic phenotype in Brandt’s voles (Lasiopodomys brandtii). PLoS One 2011, 6(5):e19913.
• [17]Ohkubo T, Tanaka M, Nakashima K: Structure and tissue distribution of chicken leptin receptor (cOb-R) mRNA. Biochim Biophys Acta 2000, 25:303-308.
• [18]Cheung CC, Thornton JE, Nurani SD, Clifton DK, Steiner RA: A reassessment of leptin’s role in triggering the onset of puberty in the rat and mouse. Neuroendocrinology 2001, 74:12-21.
• [19]Dunn IC, Sharp PJ: Photo-induction of hypothalamic gonadotrophin releasing hormone-I mRNA in the domestic chicken: a role for oestrogen? J Neuroendocrinol 1999, 11:371-375.
• [20]Ni YD, Zhou YC, Lu LZ, Chen J, Zhao RQ: Expression of GnRH-ImRNA in pineal gland of the femal Shaoxing ducks. Journal of Nanjing Agricultural University 2004, 24:135-137.
• [21]Ni YD, Zhou YC, Lu LZ, Chen J, Zhao RQ: Changes of GnRH-Iand POMC mRNA level in hypothalami of the femal Shaoxing ducks from 1 to 120 day-old after hatching. Journal of Nanjing Agricultural University 2002, 25:85-88.
• [22]Ebling FJ: The neuroendocrine timing of puberty. Reproduction 2005, 129:675-683.
• [23]Ni YD, Chen WH, Wang YJ, Zhou YC, Chen J, Zhao RQ: Changes of Serum Leptin and IGF-I During Sexual Maturation in Shaoxing Ducks. Acta Ecologae Animalis Domastici 2005, 26(4):75-77.
• [24]Block SS, Smith JM, Ehrhardt RA, Diaz MC, Rhoads RP, Van Amburgh ME, Boisclair YR: Nutritional and developmental regulation of plasma leptin in dairy cattle. J Dairy Sci 2003, 86:3206-3214.
• [25]Watanobe H, Schiöth HB: Postnatal profile of plasma leptin concentrations in male and female rats: relation with the maturation of the pituitary-gonadal axis. Regul Pept 2002, 105(1):23-28.