Aspergillus fumigatus is a saprophytic euascomycete mold with a ubiquitous presence worldwide. It is also a pervasive pathogen to immunosuppressed patients. Despite intensive work to understand its success as a pathogen, little information is known regarding the population dynamics and recent evolutionary history of this species. W e examined patterns of variation at three intergenic loci in a sample of 60 natural isolates from various parts of the world. These loci were also used to analyze site specific variation for 30 strains isolated from five localities. For both data sets no evidence of population structure was detected and there was no association between the genetic and geographic distances among different natural isolates. Thus, nothwithstanding its nearly worldwide occurrence, little evidence was found for local adaptation in A. fumigatus strains derived from diverse locations. Since conflicting observations have been made as to the amount of genetic variation within A. fumigatus, we contrast its effective population size with that of its closest relative, Neosartorya fischeri, and conclude A. fumigatus has comparatively low intraspecific genetic variation. Based on linkage disequilibrium measures A. fumigatus is inferred to have a recombining population structure.
Full conference title:
23rd Fungal Genetics Conference
- Fungal Genetics Conference 23rd (2002)