Chu Chen, Zheng Guangyong, Hu Shuanggang, Zhang Jinsong, Xie Shengsong, Ma Wubin, Ni Minjie, Tang Chunhua, Zhou Lu, Zhou Yuchuan, Liu Mofang, Li Yixue, Zhang Yonglian
State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, China; Graduate University of the Chinese Academy of Sciences, 200031, Shanghai, China.
CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031, Shanghai, China.
PLoS One. 2015 Apr 22;10(4):e0124450. doi: 10.1371/journal.pone.0124450. eCollection 2015.
Region-specific gene expression is an intriguing feature of the mammalian epididymis. This unique property is essential for sperm maturation and storage, and it also implicates stringent and multi-level regulations of gene expression. Over the past decade, the androgen-driven activation of epididymal gene transcription has been extensively studied. However, it still remains largely unexplored whether and how other regulatory mechanisms, such as miRNAs and DNA methylation, are involved in controlling regional gene expression in the epididymis. Using microarray-based approaches, we studied the regional miRNA expression and DNA methylation profiles in 4 distinct epididymal regions (initial segment, caput, corpus and cauda) of rats. We found that the miR-200 family members were more expressed in caput, compared with cauda. By GSEA analysis, the differential expression of miR-200 family between caput and cauda was shown to be negatively correlated with their predicted target genes, among which 4 bona fide targets were verified by luciferase reporter assay. Predicted target genes of miR-200 family have enriched functions in anti-apoptosis, cell transportation and development, implying the regional diversity in epididymal functions. On the other hand, we revealed epididymal DNA methylation of 2002 CpG islands and 2771 gene promoters (-3.88-0.97 kb), among which 1350 (67.43%) CpG islands and 2095 (75.60%) promoters contained region-specific DNA methylation. We observed significant and distinct functional enrichment in genes with specifically methylated promoters in each epididymal regions, but these DNA methylations did not show significant correlation with repressed gene transcription in the mature epididymis. Conclusively, we investigated the regional miRNA expression and DNA methylation in the rat epididymis and revealed a potential role of miR-200 family in gene expression regulation between caput and cauda. This may contribute to the distinct physiological function in sperm maturation / storage of caput / cauda epididymis.
区域特异性基因表达是哺乳动物附睾的一个有趣特征。这种独特的特性对于精子成熟和储存至关重要，也意味着基因表达存在严格的多层次调控。在过去十年中，雄激素驱动的附睾基因转录激活已得到广泛研究。然而，其他调控机制，如微小RNA（miRNA）和DNA甲基化，是否以及如何参与控制附睾中的区域基因表达，在很大程度上仍未得到探索。我们使用基于微阵列的方法，研究了大鼠4个不同附睾区域（起始段、头部、体部和尾部）的区域miRNA表达和DNA甲基化谱。我们发现，与尾部相比，miR-200家族成员在头部表达更高。通过基因集富集分析（GSEA），显示头部和尾部之间miR-200家族的差异表达与其预测的靶基因呈负相关，其中4个真正的靶基因通过荧光素酶报告基因检测得到验证。miR-200家族的预测靶基因在抗凋亡、细胞运输和发育方面具有丰富的功能，这暗示了附睾功能的区域多样性。另一方面，我们揭示了2002个CpG岛和2771个基因启动子（-3.88 - 0.97 kb）的附睾DNA甲基化，其中1350个（67.43%）CpG岛和2095个（75.60%）启动子含有区域特异性DNA甲基化。我们在每个附睾区域中观察到具有特异性甲基化启动子的基因存在显著且独特的功能富集，但这些DNA甲基化在成熟附睾中与受抑制的基因转录没有显著相关性。总之，我们研究了大鼠附睾中的区域miRNA表达和DNA甲基化，并揭示了miR-200家族在头部和尾部之间基因表达调控中的潜在作用。这可能有助于附睾头部/尾部在精子成熟/储存方面的不同生理功能。
