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

Ni Y, Lv J, Wang S, Zhao R - J Anim Sci Biotechnol (2013)

Bottom Line: 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.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, P. R. China.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus

LH-β mRNA expression in pituitary between LL and SL chickens at D112 and D136. Results of statistical analysis for LH-β mRNA level expressed as arbitrary units relative to β-actin mRNA. The results were expressed as mean ± S.E.M. and differences were considered significant when P < 0.05 tested by ANOVA with SPSS 11.0 for windows. Mean values with (a, b) differ significantly between LL and SL groups (P < 0.05, n = 10).
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Figure 4: LH-β mRNA expression in pituitary between LL and SL chickens at D112 and D136. Results of statistical analysis for LH-β mRNA level expressed as arbitrary units relative to β-actin mRNA. The results were expressed as mean ± S.E.M. and differences were considered significant when P < 0.05 tested by ANOVA with SPSS 11.0 for windows. Mean values with (a, b) differ significantly between LL and SL groups (P < 0.05, n = 10).

Mentions: As shown in Figure 1–5, at the age of D136, the level of GnRH-I mRNA expression in pineal gland of LL birds was significantly lower than that at D112, and was also markedly lower than un-mature SL chickens at D136 (P<0.05, n = 10). Within SL group, there was no difference of GnRH-I mRNA expression in pineal gland between D112 and D136 (P>0.05, n = 10) (Figure 1). Hypothalamic GnRH-I mRNA expression significantly increased with age in both groups (P<0.05, n = 10), however, there was no difference between LL and SL at the corresponding age (P>0.05, n = 10) (Figure 2). Figures 3, 4, 5 showed that leptin receptor mRNA expression in the hypothalamus as well as LH-β and FSH-β mRNA expression in pituitary showed the same pattern as GnRH-I gene in hypothalamus, which increased with age but showed no difference between two groups at the same age (P>0.05, n = 10). Figures 1, 2, 3, 4, 5.


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

Ni Y, Lv J, Wang S, Zhao R - J Anim Sci Biotechnol (2013)

LH-β mRNA expression in pituitary between LL and SL chickens at D112 and D136. Results of statistical analysis for LH-β mRNA level expressed as arbitrary units relative to β-actin mRNA. The results were expressed as mean ± S.E.M. and differences were considered significant when P < 0.05 tested by ANOVA with SPSS 11.0 for windows. Mean values with (a, b) differ significantly between LL and SL groups (P < 0.05, n = 10).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750458&req=5

Figure 4: LH-β mRNA expression in pituitary between LL and SL chickens at D112 and D136. Results of statistical analysis for LH-β mRNA level expressed as arbitrary units relative to β-actin mRNA. The results were expressed as mean ± S.E.M. and differences were considered significant when P < 0.05 tested by ANOVA with SPSS 11.0 for windows. Mean values with (a, b) differ significantly between LL and SL groups (P < 0.05, n = 10).
Mentions: As shown in Figure 1–5, at the age of D136, the level of GnRH-I mRNA expression in pineal gland of LL birds was significantly lower than that at D112, and was also markedly lower than un-mature SL chickens at D136 (P<0.05, n = 10). Within SL group, there was no difference of GnRH-I mRNA expression in pineal gland between D112 and D136 (P>0.05, n = 10) (Figure 1). Hypothalamic GnRH-I mRNA expression significantly increased with age in both groups (P<0.05, n = 10), however, there was no difference between LL and SL at the corresponding age (P>0.05, n = 10) (Figure 2). Figures 3, 4, 5 showed that leptin receptor mRNA expression in the hypothalamus as well as LH-β and FSH-β mRNA expression in pituitary showed the same pattern as GnRH-I gene in hypothalamus, which increased with age but showed no difference between two groups at the same age (P>0.05, n = 10). Figures 1, 2, 3, 4, 5.

Bottom Line: 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.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, P. R. China.

ABSTRACT

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.

No MeSH data available.


Related in: MedlinePlus