Viruses as indicators of contemporary host dispersal and phylogeography: an example of feline immunodeficiency virus (FIVPle) in free-ranging African lion (Panthera leo)

Abstract

Measuring contemporary dispersal in highly mobile terrestrial species is challenging, especially when species are characterized by low levels of population differentiation. Directly transmitted viruses can be used as a surrogate for traditional methods of tracking host movement. Feline immunodeficiency virus (FIV) is a species-specific lentivirus, which has an exceptionally high mutation rate and circulates naturally in wild felids. Using samples derived from 35 lion (Panthera leo) prides, we tested the prediction that FIV in lions (FIVPle) can be used to track the dispersal of individuals between prides. As FIVPle subtypes are geographically structured throughout Africa, we predicted that this marker could be used to detect phylogeographic structure of lions at smaller spatial scales. Phylogenetic analyses of FIVPle pol-RT sequences showed that core pride members (females and subadults) shared evolutionary close viral lineages which differed from neighbouring core prides, whereas sequences from sexually mature males associated with the same pride were always the most divergent. In six instances, natal pride associations of divergent male lions could be inferred, on the assumption that FIVPle infections are acquired during early life stages. Congruence between the genetic pattern of FIV and pride structure suggests that vertical transmission plays an important role in lion FIV dynamics. At a fine spatial scale, significant viral geographic structuring was also detected between lions occurring north of the Olifants River within the Kruger National Park (KNP) and those occupying the southern and central regions. This pattern was further supported by phylogenetic analyses and the confinement of FIVPle subtype E to the northern region of KNP. The study provides new insights into the use of retroviral sequences to predict host dispersal and fine-scale contemporary geographic structure in a social felid species.