Habitat loss is resulting in fragmented populations that are at elevated risk of extinction due to multiple factors, including vulnerability to stochastic events, inbreeding depression, and disease. Genetic rescue is a management option used to alleviate the effects of inbreeding via the introduction of conspecifics from larger, more viable populations into a threatened or endangered population. Florida panthers are an iconic example of a successful genetic rescue. We used a modern next generation sequencing approach to evaluate the consequences of genetic rescue on transmission patterns of feline foamy virus (FFV), an endemic retrovirus in the panther population and other pumas. We then related viral phylogenies to landscape characteristics to determine how these factors influence viral spread.
Results/Conclusions
Phylogenetic analysis revealed multiple clades of FFV with limited geographic structuring that included isolates from Florida panthers interspersed with variants from other puma and domestic cat populations. However, we identified a distinct clade consisting entirely of Florida panther isolates, including many from historic samples prior to the genetic rescue. Our results suggest FFV in the contemporary population has arisen from: (1) geographic isolation of FFV and the Florida panther in the early twentieth century, (2) contemporary FFV introductions as a result of an intentional genetic rescue event, and (3) apparent spillover of FFV from domestic cats. We further show that the rate of viral transmission increased following the genetic rescue event. Our findings highlight how isolated populations are at risk from: the introduction of pathogens, spillover from closely related species, or via management actions to preserve these populations. The pattern of spillover from domestic cats as well as direct panther to panther transmission reflects that of the pathogenic Feline Leukemia Virus and thus FFV provides a model to inform management of pathogenic outbreaks.