• Marcus M Teixeira, Luiz G P de Almeida, Paula Kubitschek-Barreira, Fernanda L Alves, Erika S Kioshima, Ana K R Abadio, Larissa Fernandes, Lorena S Derengowski, Karen S Ferreira, Rangel C Souza, Jeronimo C Ruiz, Nathalia C de Andrade, Hugo C Paes, André M Nicola, Patrícia Albuquerque, Alexandra L Gerber, Vicente P Martins, Luisa D F Peconick, Alan Viggiano Neto, Claudia B Chaucanez, Patrícia A Silva, Oberdan L Cunha, Fabiana F M de Oliveira, Tayná C dos Santos, Amanda L N Barros, Marco A Soares, Luciana M de Oliveira, Marjorie M Marini, Héctor Villalobos-Duno, Marcel M L Cunha, Sybren de Hoog, José F da Silveira, Bernard Henrissat, Gustavo A Niño-Vega, Patrícia S Cisalpino, Héctor M Mora-Montes, Sandro R Almeida, Jason E Stajich, Leila M Lopes-Bezerra, Ana T R Vasconcelos, and Maria S S Felipe.
• Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, Brazil. msueliunb@gmail.com.
• Bmc Genomics. 2014 Jan 1;15:943.

BackgroundThe fungal genus Sporothrix includes at least four human pathogenic species. One of these species, S. brasiliensis, is the causal agent of a major ongoing zoonotic outbreak of sporotrichosis in Brazil. Elsewhere, sapronoses are caused by S. schenckii and S. globosa. The major aims on this comparative genomic study are: 1) to explore the presence of virulence factors in S. schenckii and S. brasiliensis; 2) to compare S. brasiliensis, which is cat-transmitted and infects both humans and cats with S. schenckii, mainly a human pathogen; 3) to compare these two species to other human pathogens (Onygenales) with similar thermo-dimorphic behavior and to other plant-associated Sordariomycetes.ResultsThe genomes of S. schenckii and S. brasiliensis were pyrosequenced to 17x and 20x coverage comprising a total of 32.3 Mb and 33.2 Mb, respectively. Pair-wise genome alignments revealed that the two species are highly syntenic showing 97.5% average sequence identity. Phylogenomic analysis reveals that both species diverged about 3.8-4.9 MYA suggesting a recent event of speciation. Transposable elements comprise respectively 0.34% and 0.62% of the S. schenckii and S. brasiliensis genomes and expansions of Gypsy-like elements was observed reflecting the accumulation of repetitive elements in the S. brasiliensis genome. Mitochondrial genomic comparisons showed the presence of group-I intron encoding homing endonucleases (HE's) exclusively in S. brasiliensis. Analysis of protein family expansions and contractions in the Sporothrix lineage revealed expansion of LysM domain-containing proteins, small GTPases, PKS type1 and leucin-rich proteins. In contrast, a lack of polysaccharide lyase genes that are associated with decay of plants was observed when compared to other Sordariomycetes and dimorphic fungal pathogens, suggesting evolutionary adaptations from a plant pathogenic or saprobic to an animal pathogenic life style.ConclusionsComparative genomic data suggest a unique ecological shift in the Sporothrix lineage from plant-association to mammalian parasitism, which contributes to the understanding of how environmental interactions may shape fungal virulence. . Moreover, the striking differences found in comparison with other dimorphic fungi revealed that dimorphism in these close relatives of plant-associated Sordariomycetes is a case of convergent evolution, stressing the importance of this morphogenetic change in fungal pathogenesis.

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