As with other retroviruses, the MLVs replicate their genomes with relatively low fidelity. Thus, divergent viral sequences may be found in a single host organism. MLV reverse transcriptases are thought to have a slightly higher fidelity than the HIV-1 RT. Research. The Friend virus (FV) is a strain of murine leukemia virus. The Friend virus has Gammaretroviruses are an example of simple retroviruses, whereas the HIV-1, a lentivirus, is an example of a complex retrovirus. The 9.7 kb HIV-1 genome is flanked by 5′- and 3′ LTRs, which Abstract. Although endogenous retroviruses (ERVs) are known to harbor cis -regulatory elements, their role in modulating cellular immune responses remains poorly understood. Using an RNA-seq approach, we show that several members of the ERV9 lineage, particularly LTR12C elements, are activated upon HIV-1 infection of primary CD4 + T cells. The cyclin-related genes recently discovered in the genome of a fish retrovirus may play a similar role. The clearest examples of viruses that can affect the cycling and differentiation state of the infected cells are those simple viruses that have acquired oncogenes from the cell. These viruses have been of great importance in the development HIV is considered a retrovirus because of its capacity to transform RNA into DNA, reversing the natural process that takes place in cells. This is accomplished by the reverse transcriptase xMKACSr.

is hiv a retrovirus