Host–anellovirus interactions in an island ecosystem: non-human primates and rodents in Madagascar harbour diverse, rich anellovirus populations

Abstract

=3). We observed distinct anellovirus lineages in the endemic lemurs and tufted-tailed rats, which we infer to be the result of their long-term geographic isolation in Madagascar. Lemur-infecting anelloviruses, in particular, do not cluster with other primate-infecting anelloviruses. In contrast, anellovirus diversity in widespread, non-native rodents (i.e. black rats) was similar to that of closely related, globally dispersed rodent species, concordant with their later introduction to Madagascar. With our large anellovirus dataset from black rats, we examined anellovirus alpha- and beta-diversity and viral co-occurrence networks. Black rat anellovirus populations showed high intra-individual variation, but the overall pool of circulating anelloviruses was consistent across age classes and sexes. Adult relative to juvenile/subadult black rats harboured richer anellovirus populations and were more connected within the co-occurrence network. Proximity between individuals and greater intra-individual viral diversity were also linked to more virus-sharing between black rats.