Abstract：
The signaling pathway of the wingless-type mouse mammary tumor virus integration site (Wnt) plays an important role in ovarian and follicular development. In our previous study, WNT4 was shown to be involved in the selection and development of chicken follicles by upregulating the expression of follicle-stimulating hormone receptors (FSHR), stimulating the proliferation of follicular granulosa cells, and increasing the secretion of steroidal hormones. FSH also stimulates the expression of WNT4. To further explore the molecular mechanism by which FSH upregulates WNT4 and characterize the cis-elements regulating WNT4 transcription, in this study, we determined the critical regulatory regions affecting chicken WNT4 transcription. We then identified a single-nucleotide polymorphism (SNP) in this region, and finally analyzed the associations of the SNP with chicken production traits. The results showed that the 5′ regulatory region from −3354 to −2689 of WNT4 had the strongest activity and greatest response to FSH stimulation, and we identified one SNP site in this segment, −3015 (G > C), as affecting the binding of NFAT5 (nuclear factor of activated T cells 5) and respones to FSH stimulation. When G was replaced with C at this site, it eliminated the NFAT5 binding. The mRNA level of WNT4 in small yellow follicles of chickens with genotype GG was significantly higher than that of the other two genotypes. Moreover, this locus was found to be significantly associated with comb length in hens. Individuals with the genotype CC had longer combs. Collectively, these data suggested that SNP−3015 (G > C) is involved in the regulation of WNT4 gene expression by responding FSH and affecting the binding of NFAT5 and that it is associated with chicken comb length. The current results provide a reference for further revealing the response mechanism between WNT and FSH.
摘要：
无翼型小鼠乳腺肿瘤病毒整合位点(Wnt)的信号通路在卵巢和卵泡发育中起重要作用。在我们之前的研究中,WNT4通过上调卵泡刺激素受体（FSHR）的表达而参与鸡卵泡的选择和发育，刺激卵泡颗粒细胞的增殖，并增加类固醇激素的分泌。FSH还刺激WNT4的表达。为了进一步探索FSH上调WNT4的分子机制，并表征调节WNT4转录的顺式元件，在这项研究中，我们确定了影响鸡WNT4转录的关键调控区。然后我们确定了该区域的单核苷酸多态性（SNP），最后分析了SNP与鸡生产性状的相关性。结果表明，WNT4的-3354至-2689的5'调节区具有最强的活性和对FSH刺激的最大反应，我们在这一部分中确定了一个SNP位点，-3015(G>C)，影响NFAT5（活化T细胞的核因子5）的结合并响应FSH刺激。当G在此站点被C替换时，它消除了NFAT5结合。GG基因型鸡黄色小卵泡中WNT4的mRNA程度明显高于其他两种基因型。此外，发现该基因座与母鸡的梳子长度显着相关。具有基因型CC的个体具有更长的梳子。总的来说，这些数据表明，SNP-3015（G＆gt;C）通过响应FSH并影响NFAT5的结合而参与WNT4基因表达的调节，并且与鸡的梳子长度有关。本研究结果为进一步揭示WNT与FSH的反应机制提供了参考。
