| 1. |
- Ament-Velásquez, Sandra Lorena, Ph.D. 1988-, et al.
(författare)
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High-Quality Genome Assemblies of 4 Members of the Podospora anserina Species Complex
- 2024
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Ingår i: Genome Biology and Evolution. - : Oxford University Press. - 1759-6653. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- The filamentous fungus Podospora anserina is a model organism used extensively in the study of molecular biology, senescence, prion biology, meiotic drive, mating-type chromosome evolution, and plant biomass degradation. It has recently been established that P. anserina is a member of a complex of 7 closely related species. In addition to P. anserina, high-quality genomic resources are available for 2 of these taxa. Here, we provide chromosome-level annotated assemblies of the 4 remaining species of the complex, as well as a comprehensive data set of annotated assemblies from a total of 28 Podospora genomes. We find that all 7 species have genomes of around 35 Mb arranged in 7 chromosomes that are mostly collinear and less than 2% divergent from each other at genic regions. We further attempt to resolve their phylogenetic relationships, finding significant levels of phylogenetic conflict as expected from a rapid and recent diversification.
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| 2. |
- Ament-Velásquez, Sandra Lorena, M.Sc. 1988-, et al.
(författare)
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The evolution of the allorecognition gene repertoire in the Podospora anserina species complex
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Across the Tree of Life, self/non-self recognition is typically achieved through highly polymorphic loci under balancing selection. In fungi, vegetative conspecific recognition, or allorecognition, is defined by the compatibility interactions between loci known as het genes. In this study we explore the evolution of the het genes in the model fungus Podospora anserina and its closest relatives (the Podospora anserina species complex). First, we used chromosome-level genome assemblies to resolve their phylogenetic relationships. We found that the species in the complex are well defined but diversified recently and rapidly, leading to high degrees of conflict at deep branches of the phylogeny. Unlike typical orthologous genes from the complex, some allorecognition genes (het-z and het-s) show trans-species polymorphism, a hallmark of long-term balancing selection. By contrast, the het genes belonging to the HNWD family exhibit a high turn-over, with losses and duplications happening often. In particular, the species P. pseudocomata has a considerable increase of HNWD genes. Unexpectedly, we show that the HNWD paralogs have clean defined boundaries flanked by a target site duplication (TSD), implicating a DNA transposon-like mechanism in the genesis of new duplicates. Overall, our data highlights the diversity of evolutionary histories behind individual self/non-self recognition genes at short evolutionary timescales.
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| 3. |
- Cioci, Gianluca, et al.
(författare)
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Beta-propeller crystal structure of Psathyrella velutina lectin: an integrin-like fungal protein interacting with monosaccharides and calcium.
- 2006
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Ingår i: Journal of molecular biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 357:5, s. 1575-91
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Tidskriftsartikel (refereegranskat)abstract
- The lectin from the mushroom Psathyrella velutina recognises specifically N-acetylglucosamine and N-acetylneuraminic acid containing glycans. The crystal structure of the 401 amino acid residue lectin shows that it adopts a very regular seven-bladed beta-propeller fold with the N-terminal region tucked into the central cavity around the pseudo 7-fold axis. In the complex with N-acetylglucosamine, six monosaccharides are bound in pockets located between two consecutive propeller blades. Due to the repeats shown by the sequence the binding sites are very similar. Five hydrogen bonds between the protein and the sugar hydroxyl and N-acetyl groups stabilize the complex, together with the hydrophobic interactions with a conserved tyrosine and histidine. The complex with N-acetylneuraminic acid shows molecular mimicry with the same hydrogen bond network, but with different orientations of the carbohydrate ring in the binding site. The beta-hairpin loops connecting the two inner beta-strands of each blade are metal binding sites and two to three calcium ions were located in the structure. The multispecificity and high multivalency of this mushroom lectin, combined with its similarity to the extracellular domain of an important class of cell adhesion molecules, integrins, are another example of the outstanding success of beta-propeller structures as molecular binding machines in nature.
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| 4. |
- Hartmann, Fanny E., et al.
(författare)
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Size Variation of the Nonrecombining Region on the Mating-Type Chromosomes in the Fungal Podospora anserina Species Complex
- 2021
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Ingår i: Molecular biology and evolution. - : Oxford University Press. - 0737-4038 .- 1537-1719. ; 38:6, s. 2475-2492
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Tidskriftsartikel (refereegranskat)abstract
- Sex chromosomes often carry large nonrecombining regions that can extend progressively over time, generating evolutionary strata of sequence divergence. However, some sex chromosomes display an incomplete suppression of recombination. Large genomic regions without recombination and evolutionary strata have also been documented around fungal mating-type loci, but have been studied in only a few fungal systems. In the model fungus Podospora anserina (Ascomycota, Sordariomycetes), the reference S strain lacks recombination across a 0.8-Mb region around the mating-type locus. The lack of recombination in this region ensures that nuclei of opposite mating types are packaged into a single ascospore (pseudohomothallic lifecycle). We found evidence for a lack of recombination around the mating-type locus in the genomes of ten P. anserina strains and six closely related pseudohomothallic Podospora species. Importantly, the size of the nonrecombining region differed between strains and species, as indicated by the heterozygosity levels around the mating-type locus and experimental selfing. The nonrecombining region is probably labile and polymorphic, differing in size and precise location within and between species, resulting in occasional, but infrequent, recombination at a given base pair. This view is also supported by the low divergence between mating types, and the lack of strong linkage disequilibrium, chromosomal rearrangements, transspecific polymorphism and genomic degeneration. We found a pattern suggestive of evolutionary strata in P. pseudocomata. The observed heterozygosity levels indicate low but nonnull outcrossing rates in nature in these pseudohomothallic fungi. This study adds to our understanding of mating-type chromosome evolution and its relationship to mating systems.
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| 5. |
- Hensen, Noah, et al.
(författare)
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Genome-scale phylogeny and comparative genomics of the fungal order Sordariales
- 2023
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier. - 1055-7903 .- 1095-9513. ; 189
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Tidskriftsartikel (refereegranskat)abstract
- The order Sordariales is taxonomically diverse, and harbours many species with different lifestyles and large economic importance. Despite its importance, a robust genome-scale phylogeny, and associated comparative genomic analysis of the order is lacking.In this study, we examined whole-genome data from 99 Sordariales, including 52 newly sequenced genomes, and seven outgroup taxa. We inferred a comprehensive phylogeny that resolved several contentious relationships amongst families in the order, and cleared-up intrafamily relationships within the Podosporaceae. Extensive comparative genomics showed that genomes from the three largest families in the dataset (Chae-tomiaceae, Podosporaceae and Sordariaceae) differ greatly in GC content, genome size, gene number, repeat percentage, evolutionary rate, and genome content affected by repeat-induced point mutations (RIP). All genomic traits showed phylogenetic signal, and ancestral state reconstruction revealed that the variation of the properties stems primarily from within-family evolution. Together, the results provide a thorough framework for understanding genome evolution in this important group of fungi.
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