Presence of the gypsy (MDG4) retrotransposon in extracellular virus-like particles

As a first step to investigate the functional activity of gypsy virus-like particles (VLPs) we explored the possibility of preservation of its VLP in extracellular form. The preparations containing extracellular gypsy VLP from Drosophila melanogaster and D. virilis were obtained. Full-length polyA+ RNA and polyA+ RNA-DNA complexes of gypsy were observed in both preparations. The polypeptides with some specificity to gypsy nucleic acids were identified in the obtained VLP preparations. These data accompanied by morphological characteristics of samples testify the presence of intact gypsy VLP in cultured media both from D. melanogaster and D. virilis cultivated cells.