Pan Jianqiu, Shen Xu, Ouyang Hongjia, Sun Junfeng, Liufu Sui, Jiang Danli, Chen Wenjun, Peng Siyue, Xu Danning, Tian Yunbo, Huang Yunmao, He Jianhua
College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
Poult Sci. 2025 Feb;104(2):104753. doi: 10.1016/j.psj.2024.104753. Epub 2025 Jan 1.
To investigate the regulatory mechanism mediated by hypothalamic OPN5 on seasonal changes in the reproductive activities of domestic geese, 60 Magang ganders in their breeding period were selected for the experiment and evenly divided into an immunization group(OPN5-IM) and a control group. On days 0, 15 and 30, ganders in the immunized group were immunized with OPN5-KLH protein vaccine, and ganders in the control were immunized with the same amount of blank emulsified vaccine. Additionally, 120 female geese were provided to stimulate the reproductive activities of male geese. The results showed that the arrangement of spermatogenic cells was disturbed, the number of sperm decreased, and the testicular weight, seminiferous tubule area, length diameter, spermatogenic epithelium thickness decreased significantly with the natural day length prolonged. Moreover, the concentration of testosterone and LH decreased significantly while PRL increased. The prolonged photoperiod significantly affected the gene expression of GnRH-I, VIP, FSHβ, FSHR, LHβ, PRL, and PRLR in ganders. Specifically, the gene expression of GnRH-I, FSHβ, and LHβ in the hypothalamus and pituitary decreased, while the gene expression of VIP, PRL, and PRLR increased. Following OPN5 immunization, the anti-OPN5 antibody titer of ganders in the OPN5-IM group was notably higher than in the control group. The testicular degeneration was severe in OPN5-IM group compared with the control, as evidenced by a significant reduction in seminiferous tubule area, length diameter, and thickness of spermatogenic epithelium in the immunized group on day 60. Additionally, the concentrations of testosterone and LH were lower in the OPN5-IM group than in the control group, whereas PRL was higher. Moreover, OPN5 immunization significantly affected the expression of GnRH-I, PRL, and PRLR. OPN5 mRNA and protein expression were higher in the immunized group, whereas TRH, DIO2, and TSHR mRNA expressions were lower. However, DIO3 mRNA and protein were up-regulated in the immunized group. In conclusion, our results indicated that the reproductive performance of Magang geese degraded from the breeding to the non-breeding period as daylight was extended. Immunization against OPN5 increased OPN5 expression and down-regulated the TSH-DIO2/DIO3 pathway, further to affect the HPG axis and accelerate the degradation of reproductive activity. Therefore, OPN5 may play an important mediating role in light-regulating seasonal reproductive degradation in Magang geese.
为研究下丘脑视蛋白5（OPN5）介导的调控机制对家鹅繁殖活动季节性变化的影响，选取60只处于繁殖期的马岗公鹅进行实验，将其平均分为免疫组（OPN5-IM）和对照组。在第0、15和30天，给免疫组公鹅接种OPN5-KLH蛋白疫苗，给对照组公鹅接种等量的空白乳化疫苗。另外，提供120只母鹅以刺激公鹅的繁殖活动。结果表明，随着自然日长延长，生精细胞排列紊乱，精子数量减少，睾丸重量、曲细精管面积、长径、生精上皮厚度显著降低。此外，睾酮和促黄体生成素（LH）浓度显著降低，而催乳素（PRL）升高。延长光照周期显著影响公鹅下丘脑促性腺激素释放激素-I（GnRH-I）、血管活性肠肽（VIP）、促卵泡生成素β（FSHβ）、促卵泡生成素受体（FSHR）、促黄体生成素β（LHβ）、PRL和PRL受体（PRLR）的基因表达。具体而言，下丘脑和垂体中GnRH-I、FSHβ和LHβ的基因表达降低，而VIP、PRL和PRLR的基因表达升高。OPN5免疫后，OPN5-IM组公鹅的抗OPN5抗体效价显著高于对照组。与对照组相比，OPN5-IM组睾丸退化严重，60天时免疫组曲细精管面积、长径和生精上皮厚度显著减小。此外，OPN5-IM组睾酮和LH浓度低于对照组，而PRL浓度更高。而且，OPN5免疫显著影响GnRH-I、PRL和PRLR的表达。免疫组OPN5 mRNA和蛋白表达较高，而促甲状腺激素释放激素（TRH）、二碘甲状腺原氨酸脱碘酶2（DIO2）和促甲状腺激素受体（TSHR）mRNA表达较低。然而，免疫组DIO3 mRNA和蛋白上调。总之，我们的结果表明，随着日照延长，马岗鹅繁殖性能从繁殖期向非繁殖期退化。针对OPN5免疫增加了OPN5表达并下调了促甲状腺激素-DIO2/DIO3途径，进而影响下丘脑-垂体-性腺（HPG）轴并加速繁殖活动退化。因此，OPN5可能在调节马岗鹅季节性繁殖退化中起重要介导作用。
