293W Poster - Population Genetics
Wednesday June 08, 9:15 PM - 10:00 PM
Simulating neutral genetic diversity in P. vivax parasite populations
Authors: Krista Pipho; Shyamalika Gopalan; Jillian Grassia; Amy Goldberg
Affiliation: Duke University, Durham NC
Keywords: Theory & Method Development
Plasmodium vivax disease monitoring and control is increasingly guided by analysis of genetic data. This process is hindered by poor understanding of the expected neutral genetic variation in Plasmodium. The parasite’s complex lifecycle and particular epidemiology limit the utility of common population-genetic models. Here, we develop a whole-genome simulation of P. vivax that incorporates multiple realistic aspects of its lifecycle and epidemiology in a single framework. Using SLiM forward genetic simulations, we include a whole-genome simulation across 14 chromosomes incorporating the recurring bottlenecks and population expansions of the parasite’s life history, as well as asexual reproduction within hosts and sexual reproduction within vectors. A stochastic Ross-MacDonald model determines the transmission of infections between vectors and hosts. Under this model, we investigate the effect of changes in parameters such as transmission intensity and population size on the genetic diversity of parasite populations. We find that the severity of bottlenecks during transmission from mosquito to human has a greater impact on measures of variation (such as pairwise diversity or the site frequency spectrum) than the carrying capacity of parasites within a human host. This result is consistent with population-genetic theory, which holds that the historical minimum of a population's size disproportionately impacts the effective population size and genetic diversity. Moving forward, our model can be used to predict the impact of proposed disease interventions by making relevant changes to model parameters, or to infer population history. More generally, this work improves our understanding of the processes shaping neutral genetic diversity in P. vivax, which in turn helps inform interpretation of parasite relatedness and response to selective pressures.