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Author(s): Timothy Y. James (corresponding author) [1]; Frank Kauff [1]; Conrad L. Schoch [2, 36]; P. Brandon Matheny [3, 36]; Valérie Hofstetter [1, 36]; Cymon J. Cox [1, 37]; Gail [...]

Aspergillus flavus, like approximately one-third of ascomycete fungi, is thought to be cosmopolitan and clonal because it has uniform asexual morphology. A. flavus produces aflatoxin on nuts, grains, and cotton, and assumptions about its life history are being used to develop strategies for its biological control. We tested the assumptions of clonality and conspecificity in a sample of 31 Australian isolates by assaying restriction site polymorphisms from 11 protein encoding genes and DNA sequences from five of those genes. A. flavus isolates fell into two reproductively isolated clades (groups I and II). The lack of concordance among gene genealogies among isolates in one of the clades (group I) was consistent with a history of recombination. Our analysis included five strains of the closely related industrial fungus A. oryzae, all of which proved to be clonally related to group I.

Variations in the amount of mitochondrial DNA (mtDNA) haplotypes of Drosophila pseudoobscura collected in different parts of the world have been reported. Some researchers suggest that mating preference and cytoplasmic incompatibility were responsible for such large frequency changes of mtDNA haplotypes. However, two experiments conducted failed to support both hypotheses.

Frequent occurrence of recombination events disrupt stable maintenance of clonal genotypes in the halomorphic fungus Aspergillus nidulans found in the UK. A. nidulans strains belong to various heterokaryon compatibility groups, which orginated through recombination.

The colonization of land by eukaryotes probably was facilitated by a partnership (symbiosis) between a photosynthesizing organism (phototroph) and a fungus. However, the time when colonization occurred remains speculative. The first fossil land plants and fungi appeared 480 to 460 million years ago (Ma), whereas molecular dock estimates suggest an earlier colonization of land, about 600 Ma. Our protein sequence analyses indicate that green algae and major lineages of fungi were present 1000 Ma and that land plants appeared by 700 Ma, possibly affecting Earth's atmosphere, climate, and evolution of animals in the Precambrian., Plants, animals, and fungi are well adapted to life on land, but the first colonists faced a harsh physical environment (1, 2). The establishment of terrestrial eukaryotes may have been [...]

An Aspergillus fungus is the probably cause of epizootic infections causing the mass mortality of sea fan corals during the past 15 years. Four strains of the fungus involved are from the Aspergillus sydowii species, and isolates caused new infections in inoculation experiments. The virulence of A. sydowii was further tested using isolates from non-marine environments, and two from sea fans. It was concluded that isolates of A. sydowii from diseased sea fans have pathogenic potential not observed in isolates from other sources.