Extracellular vesicles (EVs) are membrane-enclosed nanoparticles containing specific repertoires of genetic material. In mammals, EVs can mediate the horizontal transfer of various cargos and signaling molecules, notably miRNA and mRNA species. Whether this form of intercellular communication prevails in other metazoans remains unclear. Here, we report the first parallel comparative morphologic and transcriptomic characterization of EVs from Drosophila and human cellular models. Electronic microscopy revealed that Drosophila, like human cells release exosome-like EVs with diameter ranging from 30 to 200 nm, which contain complex populations of transcripts. RNA-seq identified abundant ribosomal RNA pseudogenes and retrotransposons in human and Drosophila EVs. Vault RNAs and Y RNAs abounded in human samples, whereas small nucleolar RNAs involved in pseudouridylation were most prevalent in Drosophila EVs. Numerous mRNAs were identified, largely consisting of exonic sequences displaying full-length read coverage and enriched for translation and electronic transport chain functions. By analogy with human systems, these extensive similarities suggest that EVs could also enable RNA-mediated intercellular communication in Drosophila.
Overall design: We performed RNA-seq on extracellular vesicles purified from of human and Drosophila cell line cultures. S2R+ and D17 Drosophila EVs were analyzed, along with human A431 and HepG2 EVs. No ribosomal RNA depletion or polyA selection was performed on EV samples. For comparative analyses, we also analyzed total cellular RNA from Drosophila D17 and human HepG2. Ribodepletion was performed on cellular samples.
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