Department of Biology Science and Technology, Shandong First Medical University, Tai'an, 271016, PR China.
Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, 271018, PR China.
Anim Reprod Sci. 2020 Mar;214:106287. doi: 10.1016/j.anireprosci.2020.106287. Epub 2020 Jan 18.
Estrogen receptor alpha (ERα) is a ligand-activated transcription factor that regulates cellular responses to estrogens and transcription processes of target genes. In this study, changes in DNA methylation and histone modifications in the promoter region and Exon 1 of the ERα gene were analyzed to ascertain epigenetic changes associated with increased ERα mRNA abundance during reproductive maturation from 90 (egg production not yet initiated) to 160 (after egg production was initiated) d of age (d post-hatching) in chicken ovaries. The results indicate there was no difference in CpG methylation at the promoter and Exon 1 except at the region analyzed with primer pairs F2 and R2, where percentage of methylated CpG of Sites 2 and 8 after reproductive maturation was greater compared with before reproductive maturation. By using the chromatin immunuoprecipitation (ChIP) assay combined with SYBR green quantitative PCR, effects of histone modifications were evaluated, including histone H3K4 di + tri methylation, H3K9 phosphorylation and trimethylation, H3K36 methylation and H3K27 acetylation on chicken ERα mRNA transcript abundance. The results indicated that there was a greater histone H3K27 acetylation and lesser H3K36 trimethylation associated with increased abundance of ERα mRNA transcript in chicken ovaries after reproductive maturation (90 compared with 160 d of age). In consistent with this finding, the relative abundance of transcriptional coactivator p300 mRNA transcript and protein in the ovaries was markedly greater in reproductively mature than immature chickens. Findings provide insights into the epigenetic regulations of the chicken ERα gene expression that is required for chicken ovarian development.
雌激素受体 alpha（ERα）是一种配体激活的转录因子，可调节细胞对雌激素的反应和靶基因的转录过程。在这项研究中，分析了 ERα 基因启动子区域和外显子 1 中的 DNA 甲基化和组蛋白修饰变化，以确定与鸡卵巢从 90 日龄（尚未开始产卵）到 160 日龄（开始产卵后）生殖成熟过程中 ERα mRNA 丰度增加相关的表观遗传变化。结果表明，除了用引物对 F2 和 R2 分析的区域外，启动子和外显子 1 处的 CpG 甲基化没有差异，在生殖成熟后，第 2 位和第 8 位位点的甲基化 CpG 百分比与生殖成熟前相比有所增加。通过使用染色质免疫沉淀（ChIP）测定结合 SYBR 绿色定量 PCR，评估了组蛋白修饰的影响，包括组蛋白 H3K4 二 + 三甲基化、H3K9 磷酸化和三甲基化、H3K36 甲基化和 H3K27 乙酰化对鸡 ERα mRNA 转录丰度的影响。结果表明，在生殖成熟（90 日龄与 160 日龄相比）后，鸡卵巢中 ERα mRNA 转录丰度增加与组蛋白 H3K27 乙酰化增加和 H3K36 三甲基化减少有关。与这一发现一致的是，在生殖成熟的鸡卵巢中，转录共激活子 p300 mRNA 转录本和蛋白质的相对丰度明显高于不成熟的鸡。研究结果为鸡 ERα 基因表达的表观遗传调控提供了新视角，这对于鸡卵巢发育是必需的。
