Retroviruses can interact with each other in at least two different manners: recombination and pseudotyping. Retroviruses package two copies of viral RNA in each virion. When two viruses (shown at the top as blue and red) infect the same cell, some of the progeny viruses may contain two different viral RNAs, one from each parent (heterozygotic virions, shown as the virus with one copy of blue RNA and one copy of red RNA). During reverse transcription, recombination can occur to generate a viral DNA with genetic information from both parents. Dual-infected cells may also generate pseudotyped viruses that contain one or more protein from another virus. Most of the pseudotyped viruses contain envelope from a different virus. However, there are examples of a pseudotyped virus formed with all of the proteins from one virus and RNA from another (shown as blue RNA in the red virus). In these cases, the viral proteins from one virus can recognize the RNA of a different virus.
Last modified: 12 December 2008
