Viral evolution in deep time: lentiviruses and mammals

Lentiviruses are a distinctive genus of retroviruses that cause chronic, persistent infections in mammals, including humans. The emergence of pandemic HIV type-1 (HIV-1) infection during the late 20th century shaped a view of lentiviruses as ‘modern’ viruses. However, recent research has revealed an entirely different perspective, elucidating aspects of an evolutionary relationship with mammals that extends across many millions of years. Such deep evolutionary history is likely to be typical of many host–virus systems, fundamentally underpinning their interactions in the present day. For this reason, establishing the deep history of virus and host interaction is key to developing a fully informed approach to tackling viral diseases. Here, I use the example of lentiviruses to illustrate how paleovirological, geographic and genetic calibrations allow observations of virus and host interaction across a wide range of temporal and spatial scales to be integrated into a coherent ecological and evolutionary framework. Lentiviruses are a distinctive genus of retroviruses that cause chronic, persistent infections in mammals, including humans. The emergence of pandemic HIV type-1 (HIV-1) infection during the late 20th century shaped a view of lentiviruses as ‘modern’ viruses. However, recent research has revealed an entirely different perspective, elucidating aspects of an evolutionary relationship with mammals that extends across many millions of years. Such deep evolutionary history is likely to be typical of many host–virus systems, fundamentally underpinning their interactions in the present day. For this reason, establishing the deep history of virus and host interaction is key to developing a fully informed approach to tackling viral diseases. Here, I use the example of lentiviruses to illustrate how paleovirological, geographic and genetic calibrations allow observations of virus and host interaction across a wide range of temporal and spatial scales to be integrated into a coherent ecological and evolutionary framework. characteristic of the earliest diverging lineages within a clade. a well-supported clade that includes all placental mammals except Xenarthra (sloths, anteaters and armadillos) and Afrotheria (elephants, hyraxes and tenrecs). a group (usually of species or sequences) sharing a common ancestor. characteristic of the late-diverging lineages within a clade. a sequence derived from a virus that is stably integrated into the host germ line. a property of certain mathematical and computational operations that can be applied multiple times without changing the result beyond the initial application. This term is proposed here to refer to patterns of convergent evolution in measurably evolving populations characterized by frequent recapitulation of genotypic or phenotypic states. populations from which molecular sequences taken at different points in time show a significant number of genetic differences. genes sharing a common ancestor and diverged after a speciation event. the study of ancient viruses and their interactions with hosts. a type of directional evolutionary selection that acts to remove deleterious genetic variation from a population. a protein that directly inhibits viral replication.