Variation in egg production exists in commercial turkey hens, with low egg producing hens (LEPH) costing more per egg produced than high egg producing hens (HEPH). Egg production correlates with ovulation frequency, which is governed by the hypothalamic-pituitary-gonadal (HPG) axis. Ovulation is stimulated by a preovulatory surge (PS) of progesterone and luteinizing hormone, triggered by gonadotropin releasing hormone release and inhibited by gonadotropin inhibiting hormone. Differences between LEPH and HEPH were characterized by determining HPG axis plasma hormone profiles and mRNA levels for key genes, both outside and inside of the PS (n = 3 per group). Data were analyzed with a 2-way ANOVA using the mixed models procedure of SAS. In the HPG axis, plasma progesterone levels were not affected by egg production level but were elevated during the PS. In contrast, plasma estradiol levels were higher in HEPH than in LEPH but were not associated with the PS. LEPH exhibited decreased gene expression associated with ovulation stimulation and increased gene expression associated with ovulation inhibition in the hypothalamus and pituitary. In ovarian follicle cells, LEPH displayed decreased gene expression associated with progesterone, androgen, and estradiol production in the F1 follicle granulosa cells, F5 theca interna cells, and small white follicle cells, respectively. Different degrees of stimulation and inhibition within all tissues of the HPG axis were noted between LEPH and HEPH turkey hens, with HEPH showing higher expression of genes related to ovulation and steroidogenesis.

中文翻译：

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低产蛋鸡和高产蛋鸡的下丘脑-垂体-性腺轴的特征。

商用火鸡母鸡的产蛋量存在差异，低产蛋母鸡（LEPH）的成本比高产蛋母鸡（HEPH）高。产卵与排卵频率相关，排卵频率受下丘脑-垂体-性腺（HPG）轴支配。促性腺激素和促黄体激素的排卵前激增（PS）刺激排卵，促性腺激素释放激素释放，促性腺激素抑制激素抑制促排卵。LEPH和HEPH之间的差异通过确定PSG外部和内部的关键基因的HPG轴血浆激素谱和mRNA水平来表征（每组n = 3）。使用SAS的混合模型程序对数据进行2通ANOVA分析。在HPG轴上，血浆孕激素水平不受产卵量的影响，但在PS期间升高。相反，HEPH中的血浆雌二醇水平高于LEPH，但与PS无关。LEPH在下丘脑和垂体中表现出与排卵刺激相关的基因表达降低，而与排卵抑制相关的基因表达升高。在卵巢卵泡细胞中，LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示出与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织均受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。HEPH患者血浆雌二醇水平高于LEPH患者，但与PS无关。LEPH在下丘脑和垂体中表现出与排卵刺激相关的基因表达降低，而与排卵抑制相关的基因表达升高。在卵巢卵泡细胞中，LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示出与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织均受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。HEPH患者血浆雌二醇水平高于LEPH患者，但与PS无关。LEPH在下丘脑和垂体中表现出与排卵刺激相关的基因表达降低，而与排卵抑制相关的基因表达升高。在卵巢卵泡细胞中，LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示出与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。LEPH在下丘脑和垂体中表现出与排卵刺激相关的基因表达降低，而与排卵抑制相关的基因表达升高。在卵巢卵泡细胞中，LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示出与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织均受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。LEPH在下丘脑和垂体中表现出与排卵刺激相关的基因表达降低，而与排卵抑制相关的基因表达升高。在卵巢卵泡细胞中，LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示出与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织均受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织均受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。LEPH分别在F1卵泡颗粒细胞，F5 theca interna细胞和白色小卵泡细胞中显示与孕酮，雄激素和雌二醇产生相关的基因表达降低。在LEPH和HEPH火鸡之间，HPG轴的所有组织均受到不同程度的刺激和抑制，HEPH显示出与排卵和类固醇生成相关的基因更高的表达。