Research
Viral particles of the endogenous retrovirus ZAM from Drosophila melanogaster use a pre-existing endosome/exosome pathway for transfer to the oocyte
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* Corresponding authors: F Giorgi giorgif@biomed.unipi.it - C Vaury Chantal.VAURY@inserm.u-clermont1.fr
1 INSERM, U384, Faculté de Médecine, BP38, 63001 Clermont-Ferrand, France
2 Centre of Electron Microscopy, Department of Environmental Sciences, Tuscia, University Viterbo, Italy
Retrovirology 2006, 3:25 doi:10.1186/1742-4690-3-25
Published: 9 May 2006Abstract
Background
Retroviruses have evolved various mechanisms to optimize their transfer to new target cells via late endosomes. Here, we analyzed the transfer of ZAM, a retroelement from Drosophila melanogaster, from ovarian follicle cells to the oocyte at stage 9–10 of oogenesis, when an active yolk transfer is occurring between these two cell types.
Results
Combining genetic and microscopic approaches, we show that a functional secretory apparatus is required to tether ZAM to endosomal vesicles and to direct its transport to the apical side of follicle cells. There, ZAM egress requires an intact follicular epithelium communicating with the oocyte. When gap junctions are inhibited or yolk receptors mutated, ZAM particles fail to sort out the follicle cells.
Conclusion
Overall, our results indicate that retrotransposons do not exclusively perform intracellular replication cycles but may usurp exosomal/endosomal traffic to be routed from one cell to another.