Paracoccidioides restrepiensis has undergone a severe population bottleneck

Abstract

Genus Paracoccidioides now encompasses five species, P. lutzii, P. brasiliensis sensu stricto, P. americana, P. venezuelensis, and P. restrepiensis. All the paracoccidioidomycosis (PCM) cases reported in Colombia have been classified as P. restrepiensis, which was named in honor of Angela Restrepo, a leading researcher in the field of the biology of the fungus. Previous assessments of genetic diversity have suggested that Paracoccidioides species have differences in their level of polymorphism. To infer changes in effective population size, we used the Pairwise sequentially Markovian coalescent (PSMC) by generating two pseudodiploids for P. restrepiensis and one for P. brasiliensis sensu stricto. We found that P. restrepiensis diverged from its sister species recently, the divergence time from P. venezuelensis being 125,000 (± 42,000) years. The analyses using PSMC show a systematic reduction in the effective population size of P. restrepiensis with a rapid decrease in genetic variability compared to P. brasiliensis sensu stricto, which indicates that P. restrepiensis has undergone a systematic population bottleneck. None of the other two species show the dramatic effective population size reduction observed in P. restrepiensis. These comparisons suggest that the trajectory of P. restrepiensis is somehow different from the other Paracoccidioides species and poses the question regarding the biogeographic events that have led to such a dramatic population pattern.