Exosomes in human semen carry a distinctive repertoire of small non-coding RNAs with potential regulatory functions

Nucleic Acids Res. 2014 Jun;42(11):7290-304. doi: 10.1093/nar/gku347. Epub 2014 May 16.


Semen contains relatively ill-defined regulatory components that likely aid fertilization, but which could also interfere with defense against infection. Each ejaculate contains trillions of exosomes, membrane-enclosed subcellular microvesicles, which have immunosuppressive effects on cells important in the genital mucosa. Exosomes in general are believed to mediate inter-cellular communication, possibly by transferring small RNA molecules. We found that seminal exosome (SE) preparations contain a substantial amount of RNA from 20 to 100 nucleotides (nts) in length. We sequenced 20-40 and 40-100 nt fractions of SE RNA separately from six semen donors. We found various classes of small non-coding RNA, including microRNA (21.7% of the RNA in the 20-40 nt fraction) as well as abundant Y RNAs and tRNAs present in both fractions. Specific RNAs were consistently present in all donors. For example, 10 (of ∼2600 known) microRNAs constituted over 40% of mature microRNA in SE. Additionally, tRNA fragments were strongly enriched for 5'-ends of 18-19 or 30-34 nts in length; such tRNA fragments repress translation. Thus, SE could potentially deliver regulatory signals to the recipient mucosa via transfer of small RNA molecules.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Exosomes / chemistry*
  • Exosomes / ultrastructure
  • Humans
  • Male
  • MicroRNAs / analysis
  • RNA, Messenger / analysis
  • RNA, Small Untranslated / analysis*
  • RNA, Small Untranslated / chemistry
  • RNA, Transfer / analysis
  • Semen / chemistry*


  • MicroRNAs
  • RNA, Messenger
  • RNA, Small Untranslated
  • RNA, Transfer

Associated data

  • GEO/GSE56076