Discovery of a sexual cycle in the opportunistic fungal pathogen Aspergillus fumigatus

Author:

O’Gorman CM, Fuller HT, Dyer PS

Date: 19 December 2008

Abstract:

Aspergillus fumigatus is a saprotrophic fungus whose spores are ubiquitous in the atmosphere1. It is also an opportunistic human pathogen in immunocompromised individuals, causing potentially lethal invasive infections2, 3, and is associated with severe asthma and sinusitis4. The species is only known to reproduce by asexual means5, but there has been accumulating evidence for recombination and gene flow from population genetic studies5, 6, 7, 8, genome analysis9, 10, the presence of mating-type genes8, 10 and expression of sex-related genes8 in the fungus. Here we show that A. fumigatus possesses a fully functional sexual reproductive cycle that leads to the production of cleistothecia and ascospores, and the teleomorph Neosartorya fumigata is described. The species has a heterothallic breeding system; isolates of complementary mating types are required for sex to occur. We demonstrate increased genotypic variation resulting from recombination between mating type and DNA fingerprint markers in ascospore progeny from an Irish environmental subpopulation. The ability of A. fumigatus to engage in sexual reproduction is highly significant in understanding the biology and evolution of the species. The presence of a sexual cycle provides an invaluable tool for classical genetic analyses and will facilitate research into the genetic basis of pathogenicity and fungicide resistance in A. fumigatus, with the aim of improving methods for the control of aspergillosis. These results also yield insights into the potential for sexual reproduction in other supposedly ‘asexual’ fungi.

Link to DOI

Download the full article (Disclaimer)

This manuscript library of ~16,000 articles (1729-2024) related to Aspergillus and aspergillosis is intended for individual study only, and is provided as contribution to global understanding of the topic. Please refer to the publisher’s guidance about any other usage.