Genetic evolution between HIV-1 groups M and O: HIV-1/MO recombinant forms

HIV exhibits significant genetic diversity, with genetic recombination being a major evolutionary process. The co-circulation of HIV-1/M and HIV-1/O variants has led to the description of 20 HIV-1/M+O dual infections since 1998. Despite the genetic divergence between these variants, HIV-1/M+O dual infections have resulted in the emergence of HIV-1/MO intergroup recombinant forms, with 20 unique HIV-1/MO recombinant forms (URF_MO) currently described, raising the question of a possible benefit of the recombination and the modalities of their emergence.. This review summarized the current knowledge on HIV-1/MO recombinant forms, including their virological and genetic characteristics, phylogenetic analysis, genome profiles, and breakpoints number and location. This work also identified the potential impacts of HIV-1/MO recombination on diagnosis, monitoring, and treatment, as well as the replicative capacity of such recombinants. This review highlighted the greater diversity and complexity of HIV-1/MO recombinants than originally thought, offering new research perspectives on their emergence and virological properties.