| 1. |
- Ma, Li-Jun, et al.
(författare)
-
Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium.
- 2010
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 464:7287, s. 367-73
-
Tidskriftsartikel (refereegranskat)abstract
- Fusarium species are among the most important phytopathogenic and toxigenic fungi. To understand the molecular underpinnings of pathogenicity in the genus Fusarium, we compared the genomes of three phenotypically diverse species: Fusarium graminearum, Fusarium verticillioides and Fusarium oxysporum f. sp. lycopersici. Our analysis revealed lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes and account for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity, indicative of horizontal acquisition. Experimentally, we demonstrate the transfer of two LS chromosomes between strains of F. oxysporum, converting a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in F. oxysporum. These findings put the evolution of fungal pathogenicity into a new perspective.
|
|
| 2. |
- Ma, Li-Jun, et al.
(författare)
-
Genomic analysis of the basal lineage fungus Rhizopus oryzae reveals a whole-genome duplication.
- 2009
-
Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 5:7, s. e1000549-
-
Tidskriftsartikel (refereegranskat)abstract
- Rhizopus oryzae is the primary cause of mucormycosis, an emerging, life-threatening infection characterized by rapid angioinvasive growth with an overall mortality rate that exceeds 50%. As a representative of the paraphyletic basal group of the fungal kingdom called "zygomycetes," R. oryzae is also used as a model to study fungal evolution. Here we report the genome sequence of R. oryzae strain 99-880, isolated from a fatal case of mucormycosis. The highly repetitive 45.3 Mb genome assembly contains abundant transposable elements (TEs), comprising approximately 20% of the genome. We predicted 13,895 protein-coding genes not overlapping TEs, many of which are paralogous gene pairs. The order and genomic arrangement of the duplicated gene pairs and their common phylogenetic origin provide evidence for an ancestral whole-genome duplication (WGD) event. The WGD resulted in the duplication of nearly all subunits of the protein complexes associated with respiratory electron transport chains, the V-ATPase, and the ubiquitin-proteasome systems. The WGD, together with recent gene duplications, resulted in the expansion of multiple gene families related to cell growth and signal transduction, as well as secreted aspartic protease and subtilase protein families, which are known fungal virulence factors. The duplication of the ergosterol biosynthetic pathway, especially the major azole target, lanosterol 14alpha-demethylase (ERG11), could contribute to the variable responses of R. oryzae to different azole drugs, including voriconazole and posaconazole. Expanded families of cell-wall synthesis enzymes, essential for fungal cell integrity but absent in mammalian hosts, reveal potential targets for novel and R. oryzae-specific diagnostic and therapeutic treatments.
|
|
| 3. |
- Roysen, R., et al.
(författare)
-
Rethinking the diffusion of grassroots innovations : An embedding framework
- 2024
-
Ingår i: Technological forecasting & social change. - : Elsevier Inc.. - 0040-1625 .- 1873-5509. ; 200
-
Tidskriftsartikel (refereegranskat)abstract
- This paper conceptualises the ways grassroots innovations (GIs) influence sustainability transitions. While research on GI diffusion tends to use the three-pathway model (replication, scaling up and translation), this paper rethinks GI diffusion through the lenses of an embedding framework. We illustrate this framework by applying it to the empirical case of ecovillages in the Global North and South. The results show that GIs become embedded in wider society through different dynamics: expansion, reframing, circulation of knowledge, shifting material arrangements and replication. The embedding framework brings clarity to diverse dynamics of diffusion and is particularly able to grasp the cultural, cognitive, economic and environmental impacts of GI initiatives.
|
|
