College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu Province 225009, PR China.
College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu Province 225009, PR China.
Poult Sci. 2024 Mar;103(3):103422. doi: 10.1016/j.psj.2024.103422. Epub 2024 Jan 3.
The egg-laying interval (LI) directly reflects the laying performance of breeding pigeons, influenced by reproductive hormones. This study aimed to assess reproductive hormone levels in serum and the expression of related genes and their receptors in the hypothalamus and pituitary gland in 4 stages: first (LI1), third (LI3), fifth (LI5), and seventh (LI7) days. The results showed that serum gonadotropin-releasing hormone (GnRH) level decreased from LI1 to LI7 (P < 0.01) and peaked in LI1. The serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels stayed at high levels from LI1 to LI5. The FSH level decreased slightly from LI5 to LI7 (P > 0.05), but the LH level decreased rapidly (P < 0.01). The prolactin (PRL) levels significantly increased in LI5 (P < 0.01) compared with LI1 and then stayed at a high level. The GnRH1 expression in the hypothalamus had no significant change in LI (P > 0.05). However, the GnRHR first decreased from LI1 to LI3 (P < 0.05) and then increased. The FSH mRNA level in the pituitary gland decreased from LI1 to LI3 and slightly increased in LI5 (P > 0.05). The change pattern of FSHR was similar to that of FSH and peaked in LI5 (P < 0.05). The LH expression level was the highest in LI5 and significantly higher than that in LI3 and LI7 (P < 0.05). However, the LHR mRNA level decreased in LI (P < 0.05). The expression patterns of PRL and PRLR were similar; they were upregulated in LI and peaked in LI7 (P < 0.01). The expression pattern of GnRHR was similar to that of FSH, LH, and FSHR, suggesting the critical role of GnRHR in LI. Furthermore, the expression levels of these genes peaked in LI5, closely correlating with the maturation of the first largest follicle in pigeons. PRL-PRLR signaling inhibited GnRH activity to promote ovulation. This study provided a basis for further investigating the molecular mechanisms underlying the regulation of reproduction in pigeons.
产蛋间隔（LI）直接反映了种鸽的产蛋性能，受生殖激素的影响。本研究旨在评估血清中生殖激素水平以及下丘脑和垂体中相关基因及其受体的表达在以下 4 个阶段：第 1 天（LI1）、第 3 天（LI3）、第 5 天（LI5）和第 7 天（LI7）。结果表明，血清促性腺激素释放激素（GnRH）水平从 LI1 到 LI7 降低（P<0.01），并在 LI1 达到峰值。血清促卵泡激素（FSH）和黄体生成素（LH）水平从 LI1 到 LI5 保持在高水平。FSH 水平从 LI5 到 LI7 略有下降（P>0.05），但 LH 水平迅速下降（P<0.01）。催乳素（PRL）水平在 LI5 时显著升高（P<0.01），与 LI1 相比，然后保持在高水平。下丘脑 GnRH1 的表达在 LI 中没有明显变化（P>0.05）。然而，GnRHR 从 LI1 到 LI3 先下降（P<0.05），然后上升。垂体 FSH mRNA 水平从 LI1 到 LI3 下降，在 LI5 略有增加（P>0.05）。FSHR 的变化模式与 FSH 相似，在 LI5 达到峰值（P<0.05）。LH 表达水平在 LI5 时最高，明显高于 LI3 和 LI7（P<0.05）。然而，LHR mRNA 水平在 LI 中下降（P<0.05）。PRL 和 PRLR 的表达模式相似，在 LI 中上调，在 LI7 达到峰值（P<0.01）。GnRHR 的表达模式与 FSH、LH 和 FSHR 相似，表明 GnRHR 在 LI 中起着关键作用。此外，这些基因的表达水平在 LI5 时达到峰值，与鸽子中第一个最大卵泡的成熟密切相关。PRL-PRLR 信号抑制 GnRH 活性以促进排卵。本研究为进一步研究鸽子繁殖调控的分子机制提供了依据。
