Abstract
The ascomycetous fungus Nectria haematococca, (asexual name Fusarium solani), is a member of a group of >50 species known as the “Fusarium solani species complex”. Members of this complex have diverse biological properties including the ability to cause disease on >100 genera of plants and opportunistic infections in humans. The current research analyzed the most extensively studied member of this complex, N. haematococca mating population VI (MPVI). Several genes controlling the ability of individual isolates of this species to colonize specific habitats are located on supernumerary chromosomes. Optical mapping revealed that the sequenced isolate has 17 chromosomes ranging from 530 kb to 6.52 Mb and that the physical size of the genome, 54.43 Mb, and the number of predicted genes, 15,707, are among the largest reported for ascomycetes. Two classes of genes have contributed to gene expansion: specific genes that are not found in other fungi including its closest sequenced relative, Fusarium graminearum; and genes that commonly occur as single copies in other fungi but are present as multiple copies in N. haematococca MPVI. Some of these additional genes appear to have resulted from gene duplication events, while others may have been acquired through horizontal gene transfer. The supernumerary nature of three chromosomes, 14, 15, and 17, was confirmed by their absence in pulsed field gel electrophoresis experiments of some isolates and by demonstrating that these isolates lacked chromosome-specific sequences found on the ends of these chromosomes. These supernumerary chromosomes contain more repeat sequences, are enriched in unique and duplicated genes, and have a lower G+C content in comparison to the other chromosomes. Although the origin(s) of the extra genes and the supernumerary chromosomes is not known, the gene expansion and its large genome size are consistent with this species' diverse range of habitats. Furthermore, the presence of unique genes on supernumerary chromosomes might account for individual isolates having different environmental niches.
Highlights
The fungus Nectria haematococca, commonly referred to by its asexual name Fusarium solani, is a member of a monophyletic clade that includes over 50 phylogenetic species known as the ‘‘Fusarium solani species complex’’ [1,2]
General genome features Optical mapping revealed that N. haematococca mating population VI (MPVI) isolate 77
Chromosomal location of genes similar to other fungi To determine why N. haematococca MPVI might have more genes than F. graminearum and to see if these ‘‘extra’’ genes are similar to genes from other fungi, the proteome of N. haematococca MPVI was compared to the genomes of eight other sequenced fungi (F. graminearum, Aspergillus oryzae, A. nidulans, Coccidioides immitis, Chaetomium globosum, Magnaporthe oryzae, Neurospora crassa, and Saccharomyces cerevisiae)
Summary
The fungus Nectria haematococca, commonly referred to by its asexual name Fusarium solani, is a member of a monophyletic clade that includes over 50 phylogenetic species known as the ‘‘Fusarium solani species complex’’ [1,2]. F. solani is among the fungal species recovered from the highly radioactive inner parts of the damaged nuclear reactor at Chernobyl [12] These fungi are capable of growing in anaerobic conditions in the soil [13] and are tolerant to many compounds shown to be toxic to other fungi [14,15]. F. solani has been found growing in the caves at Lascaux, France where it is damaging the 15,000 year-old paintings [16] The ability of these fungi to adapt to so many different environments reflects their genetic plasticity and metabolic diversity. Individual members of this species complex can degrade hydrocarbons, organofluorine compounds, lignin, metal cyanides, and pesticides in the soil [17,18,19,20,21,22,23,24,25,26,27,28,29]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
