Epididymal Region-Specific miRNA Expression and DNA Methylation and Their Roles in Controlling Gene Expression in Rats

PLoS One. 2015 Apr 22;10(4):e0124450. doi: 10.1371/journal.pone.0124450. eCollection 2015.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Animals
  • Base Sequence
  • CpG Islands / genetics
  • DNA Methylation / genetics*
  • Epididymis / metabolism*
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Genes, Reporter
  • Luciferases / metabolism
  • Male
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Molecular Sequence Data
  • Organ Specificity / genetics
  • Promoter Regions, Genetic
  • Rats, Sprague-Dawley
  • Real-Time Polymerase Chain Reaction
  • Reproducibility of Results

Substances

  • 3' Untranslated Regions
  • MicroRNAs
  • Luciferases

Grants and funding

This work was supported by the National Basic Research Program (Grant No. 2014CB943103), National Natural Science Foundation of China (Grant No. 31171115 and Grant No. 31301225). The authors gratefully acknowledge the support of SA-SIBS scholarship program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.