背景:家鹅是季节性繁殖者,在所有家禽中繁殖能力最低。马岗鹅是一种局部短日饲养员,短光周期照射刺激其生殖活动,而长光周期抑制。探索可能影响生殖活动的表观遗传变化,我们在雄性马岗鹅长期光照的三个生殖阶段对下丘脑进行了全基因组亚硫酸氢盐测序和转录组测序.
结果:在三个比较组中确定了总共10,602个差异甲基化区域(DMRs)。我们观察到绝大多数DMRs富集在内含子区域。通过整合BS测序和RNA-seq数据,CGDMRs的甲基化变化与其相关基因的表达变化之间的相关性仅对内含子中含有CGDMRs的基因有意义。在这三个阶段中,总共获得了278个DMR相关的DEG。KEGG分析显示,DMR相关的DEGs主要参与11条通路。其中,在两个比较中,神经活性配体-受体相互作用途径均显着富集(RA与RD和RDvs.RI);Wnt信号通路,apelin信号通路,黑色素生成,钙信号通路,病灶粘连,和附着者交界处在RA与RA中显著富集RI比较。此外,两个5-羟色胺代谢基因的表达水平在生殖轴失活过程中通过其启动子区(TPH2)和内含子区(SLC18A2)的甲基化状态显着改变,分别。这些结果通过亚硫酸氢盐测序PCR(BSP)得到证实,焦磷酸测序,和实时qPCR,表明5-羟色胺代谢信号可能在降低长期光照诱导的马岗鹅生殖活动中起关键作用。此外,我们进行了代谢组学方法来研究三个阶段中神经递质的浓度,发现5-HIAA,血清素代谢途径的最后产物,RI期间下丘脑明显减少。
结论:我们的研究表明,下丘脑5-羟色胺代谢途径的甲基化状态与生殖失活有关,并为研究DNA甲基化对马岗鹅下丘脑生殖调节的影响提供了新的见解。
BACKGROUND: Domestic geese are seasonal breeders and have the lowest reproductive capacity among all poultry species. Magang geese is a topical short-day breeder, short photoperiod exposure stimulates its reproductive activity while long photoperiod inhibits. To explore epigenetic change that could influence reproductive activity, we performed whole genome bisulfite sequencing and transcriptome sequencing in the hypothalamus at three reproductive stages during long-light exposure in male Magang geese.
RESULTS: A total number of 10,602 differentially methylated regions (DMRs) were identified among three comparison groups. We observed that the vast majority of DMRs were enriched in intron regions. By integrating the BS-sequencing and RNA-seq data, the correlation between methylation changes of CG DMRs and expression changes of their associated genes was significant only for genes containing CG DMRs in their intron. A total of 278 DMR-associated DEGs were obtained among the three stages. KEGG analysis revealed that the DMR-associated DEGs were mainly involved in 11 pathways. Among them, the neuroactive ligand-receptor interaction pathway was significantly enriched in both two comparisons (RA vs.RD and RD vs.RI); the Wnt signaling pathway, apelin signaling pathway, melanogenesis, calcium signaling pathway, focal adhesion, and adherens junction were significantly enriched in the RA vs. RI comparison. In addition, the expression level of two serotonin-metabolic genes was significantly altered during reproductive axis inactivation by the methylation status of their promoter region (TPH2) and intron region (SLC18A2), respectively. These results were confirmed by Bisulfite sequencing PCR (BSP), pyrosequencing, and real-time qPCR, indicating that serotonin metabolic signaling may play a key role in decreasing the reproductive activity of Magang geese induced by long-light exposure. Furthermore, we performed a metabolomics approach to investigate the concentration of neurotransmitters among the three stages, and found that 5-HIAA, the last product of the serotonin metabolic pathway, was significantly decreased in the hypothalamus during RI.
CONCLUSIONS: Our study reveals that the methylation status of the serotonin metabolic pathway in the hypothalamus is associated with reproductive inactivation, and provided new insight into the effect of DNA methylation on the reproductive regulation of the hypothalamus in Magang geese.