RNA in cells. Some of it is of ancient viral origin and can be transferred to other cells. Image by Ryan Jeffs, via Wikimedia Commons
RNA in cells
During evolution, plants and animals have been infected by viruses and some of the virus genes are stably integrated in the genome. Two groups independently found that cells from flies and mice use at least one of these genes to facilitate communication between cells. The gene transcript and the protein it codes for are packed into a vesicle, which is released from one cell and fuses with another. In this way, content between cells is shared and this is important for neuron-neuron as well as neuron-muscle connections, and hence for learning and muscle contraction.

Read the full story: https://www.nature.com/articles/d41586-018-00492-w

Scientific publications: http://dx.doi.org/10.1016/j.cell.2017.12.024 and http://dx.doi.org/10.1016/j.cell.2017.12.022