Comparative genomics reveals high biological diversity and specific adaptations in the industrially and medically important fungal genus Aspergillus

Background: The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial
applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of
food, and an important genetic model. The genome sequences of eight aspergilli have already been explored to
investigate aspects of fungal biology, raising questions about evolution and specialization within this genus.
Results: We have generated genome sequences for ten novel, highly diverse Aspergillus species and compared these
in detail to sister and more distant genera. Comparative studies of key aspects of fungal biology, including primary and
secondary metabolism, stress response, biomass degradation, and signal transduction, revealed both conservation and
diversity among the species. Observed genomic differences were validated with experimental studies. This revealed
several highlights, such as the potential for sex in asexual species, organic acid production genes being a key feature of
black aspergilli, alternative approaches for degrading plant biomass, and indications for the genetic basis of stress
response. A genome-wide phylogenetic analysis demonstrated in detail the relationship of the newly genome
sequenced species with other aspergilli.
Conclusions: Many aspects of biological differences between fungal species cannot be explained by current knowledge
obtained from genome sequences. The comparative genomics and experimental study, presented here, allows for the first
time a genus-wide view of the biological diversity of the aspergilli and in many, but not all, cases linked genome
differences to phenotype. Insights gained could be exploited for biotechnological and medical applications of fungi.