The pituitary directly regulates the reproductive process through follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Transcriptomic research on the pituitaries of ewes with different FecB (fecundity Booroola) genotypes has shown that some key genes and lncRNAs play an important role in pituitary function and sheep fecundity. Our previous study found that ewes with FecB + + genotypes (without FecB mutation) still had individuals with more than one offspring per birth. It is hoped to analyze this phenomenon from the perspective of the pituitary transcriptome. The 12 Small Tail Han Sheep were equally divided into polytocous sheep in the follicular phase (PF), polytocous sheep in the luteal phase (PL), monotocous sheep in the follicular phase (MF), and monotocous sheep in the luteal phase (ML). Pituitary tissues were collected after estrus synchronous treatment for transcriptomic analysis. A total of 384 differentially expressed genes (DEGs) (182 in PF vs. MF and 202 in PL vs. ML) and 844 differentially expressed lncRNAs (DELs) (427 in PF vs. MF and 417 in PL vs. ML) were obtained from the polytocous-monotocous comparison groups in the two phases. Functional enrichment analysis showed that the DEGs in the two phases were enriched in signaling pathways known to play an important role in sheep fecundity, such as calcium ion binding and cAMP signaling pathways. A total of 1322 target relationship pairs (551 pairs in PF vs. MF and 771 pairs in PL vs. ML) were obtained for the target genes prediction of DELs, of which 29 DEL-DEG target relationship pairs (nine pairs in PF vs. MF and twenty pairs in PL vs. ML). In addition, the competing endogenous RNA (ceRNA) networks were constructed to explore the regulatory relationships of DEGs, and some important regulatory relationship pairs were obtained. According to the analysis results, we hypothesized that the pituitary first receives steroid hormone signals from the ovary and uterus and that VAV3 (Vav Guanine Nucleotide Exchange Factor 3), GABRG1 (Gamma-Aminobutyric Acid A Receptor, Gamma 1), and FNDC1 (Fibronectin Type III Domain Containing 1) played an important role in this process. Subsequently, the reproductive process was regulated by gonadotropins, and IGFBP1 (Insulin-like Growth Factor Binding Protein 1) was directly involved in this process, ultimately affecting litter size. In addition, TGIF1 (Transforming Growth Factor-Beta-Induced Factor 1) and TMEFF2 (Transmembrane Protein With EGF Like And Two Follistatin Like Domains 2) compensated for the effect of the FecB mutation and function by acting on TGF-β/SMAD signaling pathway, an important pathway for sheep reproduction. These results provided a reference for understanding the mechanism of multiple births in Small Tail Han Sheep without FecB mutation.

中文翻译：

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影响FecB++小尾寒羊繁殖的垂体关键mRNA和lncRNA

垂体通过卵泡刺激素（FSH）和黄体生成素（LH）直接调节生殖过程。对不同FecB（fecundity Booroola）基因型母羊垂体的转录组研究表明，一些关键基因和lncRNA在垂体功能和绵羊繁殖力中发挥着重要作用。我们之前的研究发现，具有FecB++基因型（无FecB突变）的母羊仍然有每胎生育多个后代的个体。希望从垂体转录组的角度来分析这一现象。将12只小尾寒羊等分为卵泡期多胎羊(PF)、黄体期多胎羊(PL)、卵泡期单胎羊(MF)、黄体期单胎羊(ML) 。发情同步处理后收集垂体组织进行转录组分析。总共获得了384个差异表达基因（DEG）（PF与MF中182个，PL与ML中202个）和844个差异表达lncRNA（DEL）（PF与MF中427个，PL与ML中417个）来自两个阶段的多胎-单胎对照组。功能富集分析表明，两个阶段的DEG在已知在绵羊繁殖力中起重要作用的信号通路中富集，例如钙离子结合和cAMP信号通路。 DEL的靶基因预测共获得1322对（PF vs MF 551对，PL vs ML 771对），其中DEL-DEG靶关系对29对（PF vs ML 9对）。 MF 和 PL 与 ML 中的 20 对）。此外，还构建了竞争性内源RNA（ceRNA）网络来探索DEG的调控关系，并获得了一些重要的调控关系对。根据分析结果，我们假设垂体首先接收来自卵巢和子宫的类固醇激素信号，VAV3（Vav鸟嘌呤核苷酸交换因子3）、GABRG1（γ-氨基丁酸A受体，γ1）和FNDC1（纤连蛋白） III型结构域包含1)在此过程中发挥了重要作用。随后，生殖过程受到促性腺激素的调节，IGFBP1（胰岛素样生长因子结合蛋白1）直接参与这一过程，最终影响产仔数。此外，TGIF1（转化生长因子-β诱导因子1）和TMEFF2（具有EGF样和两个卵泡抑素样结构域的跨膜蛋白2）通过作用于TGF-β/SMAD信号通路来补偿FecB突变和功能的影响，是羊繁殖的重要途径。这些结果为了解FecB突变小尾寒羊的多胎机制提供了参考。