Basidiomycete Species Research Articles

PRODUCTION AND ANALYSIS OF ENZYME PREPARATIONS OF OXIDOREDU CTASES OF SOME BASIDIOMY CETES

Aim. To obtain and analyze the oxidoreductase enzyme preparations of some species of Basidiomycetes. Methods. The strains Agrocybe cylindracea 167; Fistulina hepatica Fh-08 and Pleurotus ostreatus P-208 were used as the producers of oxidoreductases. The selected strains of Basidiomycetes were cultured on modified for each strain glucose-peptone medium. Fractionation of the enzyme from the culture filtrate and mycelium aqueous extracts was carried out by salting out with ammonium sulfate. The obtained solutions of protein fractions were further purified by dialysis and gel filtration on Molselekt pellet G-50 and G-75. Results. The enzyme preparations of extracellular and intracellular oxidoreductases such as peroxidase, catalase and superoxide dismutase were obtained from the cultures of Basidiomycetes. Basidiomycetes strains which were tested had individual characteristics of enzymes and enzymatic activity, pH and thermal stability. These strains of Basidiomycetes have a higher level of activity of extracellular oxidoreductases compared with intracellular. Maximum peroxidase activity of the enzyme preparation of A. cylindracea strain 167 was marked at 6.2±0.2 U/mg, catalase of strain P. ostreatus P-208 was marked at 9181±293 MAb/mg and superoxide dismutase of strain F. hepatica Fh-08 was marked at 101.6±3.5 U/mg. All enzymes are stable in the pH range of 5–10 and at temperature from 20 to 40 °C. Conclusion. New antioxidant enzymes Basidiomycetes Agrocybe cylindracea, Fistulina hepatica, Pleurotus ostreatus were obtained. There individual properties: enzyme activity, pH and temperature stability were established. According to the established properties are not inferior to the selected enzymes used in industry and they are promising for practical application.

The lectins occurrence in selected Basidiomycetes species growing in south districts of Poland

The screening examinations for the occurrence of lectins in fruit-bodies of <i>Basidiomycetes</i> collected in south part of Poland were performed on the basis of the degree of agglutination activity extracts on human and animal erythrocytes. The results were compared with those of other authors.

Basidioascus persicus sp. nov., a yeast-like species of the order Geminibasidiales isolated from soil.

A novel species of basidiomycetes was isolated from kitchen garden soil in Shahryar city, Tehran province, Iran. Molecular and conventional methods were employed to identify and classify this single isolate. Morphologically, the isolate was considered yeast-like with hyaline and oval cells reproducing by monopolar budding, forming ballistoconidia, hyphae, arthroconidia and didymospores. Basidia and basidiospores resembling those produced by Basidioascus species were observed. Sequencing and Bayesian phylogenetic analysis of rRNA genes and the internal transcribed spacer region revealed its sister relationship to described species of the genus Basidioascus. Assimilation and fermentation tests, cell-wall carbohydrate analysis and enzyme activity tests were performed to provide insight into the metabolism of the isolate. Based on morphology, physiology and phylogeny of rRNA gene sequences, the isolate was shown to represent a novel species of the genus Basidioascus, described as Basidioascus persicus sp. nov. (holotype IBRC P1010180(T) = ex-type IBRC M30078(T) = isotype CBS 12808(T)). The MycoBank number of the novel species is MB 804703. An emended description of the genus Basidioascus is also provided.

Sequence diversity and gene expression analyses of expansin-related proteins in the white-rot basidiomycete, Phanerochaete carnosa

Expansin and expansin-related proteins loosen plant cell wall architectures and are widely distributed in several types of organisms, including plants, fungi and bacteria. Here we describe sequence diversity and unique gene expression profiles of multiple expansin-related proteins identified in the basidiomycete, Phanerochaete carnosa. The protein sequences were homologous to loosenin, an expansin-related protein reported in the basidiomycete, Bjerkandera adusta. We identified homologous sequences of each of those P. carnosa proteins in many basidiomycete species. Twelve P. carnosa loosenin-like proteins (LOOLs) were classified into two subgroups according to sequence homology. Conservation of polysaccharide-binding amino acid residues was stricter in subgroup A. Subgroup A sequences included a conserved 8–9 amino acid insertion in a polysaccharide-binding groove whereas subgroup B contained a 12–18 amino acid insertion next to the binding groove. The P. carnosa genome also encodes the expansin-related protein, DREX1, which adopts a loosenin-like structure but has lower sequence homology to other LOOLs. The gene expression analysis of those proteins showed distinct patterns that were not significantly related to subgroupings. The variation in the protein sequences and gene expression patterns, and wide distribution among the basidiomycota, suggest that the diverse cell wall loosening proteins contribute to effective plant cell wall association and utilization by basidiomycetes.

New lichen-associated bulbil-forming species of Cantharellales (Basidiomycetes)

AbstractTwo new genera and four new species of bulbil-forming basidiomycetes are described. Phylogenetic analyses of nuLSU and ITS sequences place them in Cantharellales. A facultative lichenicolous species with yellow to orange-yellow bulbils from South America groups with the type of Burgella and is consequently described as B. lutea. The new species and genus Burgellopsis nivea is introduced for material from Scotland with white bulbils overgrowing saxicolous lichens. An obligate lichenicolous species with particularly large, applanate bulbils developing over Peltigerales in South America could not be placed accurately using ITS sequences and is described as the new species and genus Bulbilla applanata. A European species with brown, facultatively lichenicolous bulbils grouped with Ceratobasidium and Thanatephorus species and is described as the new Ceratobasidium bulbillifaciens.

Yeasts of the White Sea intertidal zone and description of Glaciozyma litorale sp. nov.

The intertidal yeast communities inhabiting various environments in the territories of the White Sea Biological Station "Kartesh" (WSBS ZIN RAS) and the N.A. Pertsov White Sea Biological Station (WSBS MSU) were studied. A total of 31 yeast species were isolated using a conventional plating technique and identified using molecular methods. The yeast community of the White Sea intertidal zone consists of members that are typical for marine substrates, ubiquist species that are common in water and in low-temperature terrestrial environments, and a group of species that was isolated from marine substrates for the first time. The most diverse yeast communities formed on the surface of marine algae and in silt. Metschnikowia zobellii, which is a typical inhabitant of northern seas, was the most abundant yeast on algae from both biological stations. A new basidiomycetous yeast species, which was described in this work as Glaciozyma litorale sp. nov., dominated in the silt samples. The type strain of this new species is K94b(T) (=KBP 4246(T)=VKPM Y-3850(T)=PYCC 6252(T)=CBS 12957(T)=DSM 28204(T)); MycoBank registration number is MB 805475.

Airborne molds and mycotoxins in Serpula lacrymans–damaged homes

For some years, the degradation of homes by the dry rot fungus Serpula lacrymans increased. This study described, for the first time, the fungal contamination in homes located in Low–Normandy (France) and damaged by Serpula lacrymans. Wood–decaying fungi, airborne molds, fungal species growing on building materials were investigated by cultural and molecular methods. Mycotoxins in the air were quantified by HPLC–MS/MS and the mutagenicity of fungal aerosols was also evaluated using the Ames test. The results showed that Serpula lacrymans was detected in the air for one third of homes with sometimes the co–occurrence of other ligninolytic basidiomycetes species like Donkioporia expansa. Various molds in the air and on materials (117 and 103 species, respectively) were also identified indicating the complexity of indoor mycoflora. Certain recurrent species like Aspergillus versicolor and Penicillium fellutanum were observed both on building materials and in the air. The presence of cellulolytic molds in fungal aerosols and on building materials could be used as an indicator of home degradation. Airborne culturable fungal levels were measured up to 5.8x105 Colony Forming Units (CFU) per cubic meter of the air (CFU/m3) depending on the home. Fungal concentrations also depended on the type of collector (filter or liquid) and were significantly correlated with the median of particles between 2–15μm in size. Two mycotoxins (alternariol and/or ochratoxin A) were observed in 4 homes but no mutagenic activity was found.

Nitrogen and carbon reallocation in fungal mycelia during decomposition of boreal forest litter.

Boreal forests are characterized by spatially heterogeneous soils with low N availability. The decomposition of coniferous litter in these systems is primarily performed by basidiomycete fungi, which often form large mycelia with a well-developed capacity to reallocate resources spatially- an advantageous trait in heterogeneous environments. In axenic microcosm systems we tested whether fungi increase their biomass production by reallocating N between Pinus sylvestris (Scots pine) needles at different stages of decomposition. We estimated fungal biomass production by analysing the accumulation of the fungal cell wall compound chitin. Monospecific systems were compared with systems with interspecific interactions. We found that the fungi reallocated assimilated N and mycelial growth away from well-degraded litter towards fresh litter components. This redistribution was accompanied by reduced decomposition of older litter. Interconnection of substrates increased over-all fungal C use efficiency (i.e. the allocation of assimilated C to biomass rather than respiration), presumably by enabling fungal translocation of growth-limiting N to litter with higher C quality. Fungal connection between different substrates also restricted N-mineralization and production of dissolved organic N, suggesting that litter saprotrophs in boreal forest ecosystems primarily act to redistribute rather than release N. This spatial integration of different resource qualities was hindered by interspecific interactions, in which litters of contrasting quality were colonised by two different basidiomycete species. The experiments provide a detailed picture of how resource reallocation in two decomposer fungi leads to a more efficient utilisation of spatially separated resources under N-limitation. From an ecosystem point of view, such economic fungal behaviour could potentially contribute to organic matter accumulation in the litter layers of boreal forests.

A Taxonomic Study of Wood-Rotting Basidiomycetes at the Molave Forest of San Fernando City, La Union Province, Philippines

A taxonomic study of the wood-rotting basidiomycetes was conducted at the Molave Forest of San Fernando City, La Union, Northern Luzon, Philippines. This mountainous forest located in the eastern boundaries of the City is being considered as one of the most important forest ecosystems in Ilocos Region, thereby indicating the need for conservation and protection. This paper attempts to document all the macroscopic fungal basidiomycetous species in the area by preparing taxonomic accounts based on an extensive systematic collection and by facilitating the identification or recognition of each fungal species. As there has been no comprehensive work done on the diversity of macroscopic fungi in this area, hence this study was conducted. Using transect line (TL) method, four transect lines were established from the baseline (100m asl) toward the peak (300m asl) with 10m x 25m quadrat sampling each transect line and an interval of 50 meters between quadrats. All in all 20 quadrats were laid out. The fungal species within the quadrats along the TLs were identified and recorded. This study of wood-rotting basidiomycetes in the molave forest of La Union documented fifty one species. Each species is described including substrata/hosts, synonymies, and habitat. Some of these species, being the most destructive fungi are largely responsible for the decay of living trees. We found out that fungal species richness decreased if the condition of the area is relatively dry. Â Keywords - basidiomycetes, molave forest, field survey, macrofungi, taxonomic study, species richness, wood-rotting, San Fernando City, Philippines. Â

Systematic Identification and Evolutionary Analysis of Catalytically Versatile Cytochrome P450 Monooxygenase Families Enriched in Model Basidiomycete Fungi

Genome sequencing of basidiomycetes, a group of fungi capable of degrading/mineralizing plant material, revealed the presence of numerous cytochrome P450 monooxygenases (P450s) in their genomes, with some exceptions. Considering the large repertoire of P450s found in fungi, it is difficult to identify P450s that play an important role in fungal metabolism and the adaptation of fungi to diverse ecological niches. In this study, we followed Sir Charles Darwin’s theory of natural selection to identify such P450s in model basidiomycete fungi showing a preference for different types of plant components degradation. Any P450 family comprising a large number of member P450s compared to other P450 families indicates its natural selection over other P450 families by its important role in fungal physiology. Genome-wide comparative P450 analysis in the basidiomycete species, Phanerochaete chrysosporium, Phanerochaete carnosa, Agaricus bisporus, Postia placenta, Ganoderma sp. and Serpula lacrymans, revealed enrichment of 11 P450 families (out of 68 P450 families), CYP63, CYP512, CYP5035, CYP5037, CYP5136, CYP5141, CYP5144, CYP5146, CYP5150, CYP5348 and CYP5359. Phylogenetic analysis of the P450 family showed species-specific alignment of P450s across the P450 families with the exception of P450s of Phanerochaete chrysosporium and Phanerochaete carnosa, suggesting paralogous evolution of P450s in model basidiomycetes. P450 gene-structure analysis revealed high conservation in the size of exons and the location of introns. P450s with the same gene structure were found tandemly arranged in the genomes of selected fungi. This clearly suggests that extensive gene duplications, particularly tandem gene duplications, led to the enrichment of selective P450 families in basidiomycetes. Functional analysis and gene expression profiling data suggest that members of the P450 families are catalytically versatile and possibly involved in fungal colonization of plant material. To our knowledge, this is the first report on the identification and comparative-evolutionary analysis of P450 families enriched in model basidiomycetes.

Leucosporidium escuderoi f.a., sp. nov., a basidiomycetous yeast associated with an Antarctic marine sponge

A basidiomycetous yeast, strain E2A-C3-II, was isolated from a marine sponge (Hymeniacidon sp.) collected at a depth of 6 m in Fildes Bay, King George Island, Antarctica. The phylogenetic analysis revealed that the yeast isolated is related to Leucosporidium drummii, Leucosporidiella muscorum and to the Leucosporidium scottii group, including Leucosporidiella creatinivora and Leucosporidiella yakutica. The analysis of the nucleotide differences and the genetic distances of the D1/D2 domain of the LSU rDNA gene and 5.8S ITS regions support that strain E2A-C3-II represents a new species. The novel species can be distinguished from L. drummii by its ability to assimilate L-sorbose, L-rhamnose, lactose and ribitol. The maximum temperature for growth was 25 °C. On the basis of morphological, biochemical and physiological characterization, and phylogenetic and nucleotide analysis, a novel basidiomycetous yeast species, Leucosporidium escuderoi f.a., sp. nov., is proposed. The type strain is E2A-C3-II(T) (=CBS 12734(T) =CECT 13080(T)). The Mycobank ( http://www.mycobank.org ) accession number is MB 804654. The nucleotide sequences of D1/D2 domain of the LSU rDNA gene and 5.8S-ITS regions obtained in this work have been deposited in Genbank under the Accession numbers JN181009 and JN197600, respectively.

Ethnomycological studies on some macro-fungi in Rupandehi District, Nepal

This ethnomycological investigation explores the wild edible microfungi with their identification and documentation of nutritional potential and indigenous knowledge. The study area occupies 154.75 hectare-land, and lies within a narrow limit of altitude between 110 m and 165 m above sea level in tropical deciduous riverine forest. Amanita caesarea, A. chepangiana, A. pantherina, Agaricus augustus, Coprinus comatus, C. plicatilis, Macrolepiota fuliginosa, M. rhacodes, Russula emetica, R. foetens, R. nigricans, Scleroderma bovista, S. citrinum, Termitomyces clypeatus and T. eurhizeus are found to be dominant. The collected samples represented 27 species of Basidiomycetes belonging to 6 orders, 13 families and 18 genera. The dried specimens are housed in the Tribhuvan University Central Herbarium, Kirtipur, Kathmandu, Nepal. The area embraces many mycophagous ethnic communities. The mycoelements prevailing in this area need sustainable conservation and utilization. Banko Janakari, Vol. 23, No. 1, Page 51-56 DOI: http://dx.doi.org/10.3126/banko.v23i1.9467

Co-existence and interaction between myxomycetes and other organisms in shared niches

The ecology of myxomycetes co-existing with the <em>Latridiidae</em> (Coleoptera), bryophytes and ascomycetous, basidiomycetous and anamorphic fungi were studied in Crimea and at different locations on the left bank of Ukraine. Results from the left bank indicate that the <em>Latridiidae</em> feed on myxomycetes. Colonies of the most common 13 myxomycete species (which included <em>Stemonitis axifera</em> (Bull.) Macbr., <em>S. fusca</em> Roth, <em>S. splendens</em> Rost., <em>Fuligo septica</em> (L.) Wigg. and <em>Mucilago crustacea</em> Wigg.) were inhabited by 5 species of the <em>Latridiidae</em>. Myxomycete spores were present in guts of 19 of the 25 beetle specimens investigated. Beetles <em>Latridius hirtus, Enicmus rugosus</em> and <em>E fungicola</em> seem to be obligate myxomycete feeders, while <em>Corticarina truncatella</em> was clearly facultative. 13 species of myxomycetes were recorded on 9 species of moss and 3 species of liverwort developing on decaying wood or bark in the Crimean Nature Reserve. Relations between myxomycetes and bryophytes on woody substrata are spatial rather than trophic, and are possibly regulated by specific microclimatic conditions inside bryophyte thallomes. 69 species of myxomycetes were found co-existing with 36 species of ascomycetes, 21 species of basidiomycetes and 9 species of anamorphic fungi in the Crimean Nature Reserve. Associations formed by myxomycetes and fungi on different woody substrata are analyzed.

Comparison of the Interleukin-1β-Inducing Potency of Allergenic Spores from Higher Fungi (Basidiomycetes) in a Cryopreserved Human Whole Blood System

Background: Spores from basidiomycete fungi (basidiospores) are highly prevalent in the atmosphere of urban and rural settings. Studies have confirmed their potential to affect human health as allergens. Less is known about their potential to serve as stimuli of the innate immune system and induce proinflammatory reactions. Methods: In this study, we evaluated the proinflammatory potential of spores from 11 allergenic basidiomycete species (gilled: Pleurotus ostreatus,Oudemansiella radicata,Armillaria tabescens,Coprinus micaceus,Pluteus cervinus, and Chlorophyllum molybdites, and nongilled: Pisolithus arhizus,Merulius tremellosus,Calvatia cyathiformis,Lycoperdon pyriforme, andBoletus bicolor) based on their potency to induce the release of the proinflammatory cytokine interleukin (IL)-1β in a cryopreserved human whole blood system. In addition, the roles of morphological features of the spores (surface area, shape, and pigmentation) were examined for their role in the IL-1β-including potency of spores. Peripheral blood from healthy volunteers was collected, pooled, and cryopreserved. After stimulating the cryopreserved pooled blood with 10⁶ to 10³ basidiospores/ml, the concentration of IL-1β in culture supernatants was determined with ELISA. Results: Basidiospores manifested concentration-dependent IL-1β-inducing potency, which was more marked among basidiospores from gilled basidiomycetes. At higher concentrations of basidiospores, the IL-1β-inducing potency could be differentiated in the cryopreserved human whole blood system. Morphological features did not correlate with the IL-1β-inducing potency of the basidiospores, suggesting that nonmorphological properties modulate the IL-1β-inducing potency. Conclusion: Our data provide evidence of the proinflammatory potential of basidiospores, and the utility of cryopreserved human whole blood as a human-based in vitro system to study the immune reactivity of allergenic basidiospores.

Some Wild Mushrooms of Rupandehi District, West Nepal

This mycological investigation carried out at natural as well as community managed forest, of Rupandehi district, western terai and siwaliks region of Nepal. Samples were collected in different area ranging between 90 and 1229 masl in tropical deciduous riverine forest, to subtropical deciduous hill forest. This paper highlights on common wild mushrooms Amanita chepangiana, Geastrum fimbriatum, Macrolepiota procera, Pycnoporus cinnabarinus, Schizophyllum commune, Scleroderma bovista and Sparassis crispa. The collected samples represented seven species of Basidiomycetes belongs to four order and seven families. The specimens were deposited in the Tribhuvan University Central Herbarium, (TUCH), Kathmandu, Nepal. BIBECHANA 10 (2014) 34-43 DOI: http://dx.doi.org/10.3126/bibechana.v10i0.9309

The genetic structure of the A mating-type locus of Lentinula edodes

The Shiitake mushroom, Lentinula edodes (Berk.) Pegler is a tetrapolar basidiomycete with two unlinked mating-type loci, commonly called the A and B loci. Identifying the mating-types in shiitake is important for enhancing the breeding and cultivation of this economically-important edible mushroom. Here, we identified the A mating-type locus from the first draft genome sequence of L. edodes and characterized multiple alleles from different monokaryotic strains. Two intron-length polymorphism markers were developed to facilitate rapid molecular determination of A mating-type. L. edodes sequences were compared with those of known tetrapolar and bipolar basidiomycete species. The A mating-type genes are conserved at the homeodomain region across the order Agaricales. However, we observed unique genomic organization of the locus in L. edodes which exhibits atypical gene order and multiple repetitive elements around its A locus. To our knowledge, this is the first known exception among Homobasidiomycetes, in which the mitochondrial intermediate peptidase (mip) gene is not closely linked to A locus.

Diversity and evolution of ABC proteins in basidiomycetes

ABC proteins constitute one of the largest families of proteins. They are implicated in wide variety of cellular processes ranging from ribosome biogenesis to multidrug resistance. With the advance of fungal genomics, the number of known fungal ABC proteins increases rapidly but the information on their biological functions remains scarce. In this work we extended the previous analysis of fungal ABC proteins to include recently sequenced species of basidiomycetes. We performed an identification and initial cataloging of ABC proteins from 23 fungal species representing 10 orders within class Agaricomycotina. We identified more than 1000 genes coding for ABC proteins. Comparison of sets of ABC proteins present in basidiomycetes and ascomycetes revealed the existence of two groups of ABC proteins specific for basidiomycetes. Results of survey should contribute to the better understanding of evolution of ABC proteins in fungi and support further experimental work on their characterization.

Mycodiversity at Sankarnagar Community Forest, Rupandehi Distri

This investigation explored the diversity of higher fungi with their identification, documentation and utilization. The study area covered 549 ha, which lies within a narrow limit of altitude between 165 and 200 masl, in tropical deciduous riverine forest. Amanita chepangiana, A. pantherina, Macrolepiota fuliginosa, M. rhacodes, Russula emetica, R. foetens, R. nigricans, Scleroderma citrinum, S, bovista, Termitomyces clypeatus and T. eurhizeus were found to be dominant. The collected samples represented 29 species of Basidiomycetes belonging to 7 orders, 18 families and 25 genera. The dried specimens housed at Tribhuvan University Central Herbarium (TUCH), Kirtipur, Kathmandu. The mycoelements prevailing in this area need sustainable conservation and utilization. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 75-80 DOI: http://dx.doi.org/10.3126/njst.v14i1.8925

The Implementation of the Golden Ratio to the Healthy Human Heart

Abstract Sexual development is a key evolutionary innovation of eukaryotes. In many species, mating involves interaction between compatible mating partners that can undergo cell and nuclear fusion and subsequent steps of development including meiosis. Mating compatibility in fungi is governed by mating type determinants, which are localized at mating type (MAT) loci. In basidiomycetes, the ancestral state is hypothesized to be tetrapolar (bifactorial), with two genetically unlinked MAT loci containing homeodomain transcription factor genes (HD locus) and pheromone and pheromone receptor genes (P/R locus), respectively. Alleles at both loci must differ between mating partners for completion of sexual development. However, there are also basidiomycete species with bipolar (unifactorial) mating systems, which can arise through genomic linkage of the HD and P/R loci. In the order Tremellales, which is comprised of mostly yeast-like species, bipolarity is found only in the human pathogenic Cryptococcus species. Here, we describe the analysis of MAT loci from the Trichosporonales, a sister order to the Tremellales. We analyzed genome sequences from 29 strains that belong to 24 species, including two new genome sequences generated in this study. Interestingly, in all of the species analyzed, the MAT loci are fused and a single HD gene is present in each mating type. This is similar to the organization in the pathogenic Cryptococci, which also have linked MAT loci and carry only one HD gene per MAT locus instead of the usual two HD genes found in the vast majority of basidiomycetes. However, the HD and P/R allele combinations in the Trichosporonales are different from those in the pathogenic Cryptococcus species. The differences in allele combinations compared to the bipolar Cryptococci as well as the existence of tetrapolar Tremellales sister species suggest that fusion of the HD and P/R loci and differential loss of one of the two HD genes per MAT allele occurred independently in the Trichosporonales and pathogenic Cryptococci. This finding supports the hypothesis of convergent evolution at the molecular level towards fused mating-type regions in fungi, similar to previous findings in other fungal groups. Unlike the fused MAT loci in several other basidiomycete lineages though, the gene content and gene order within the fused MAT loci are highly conserved in the Trichosporonales, and there is no apparent suppression of recombination extending from the MAT loci to adjacent chromosomal regions, suggesting different mechanisms for the evolution of physically linked MAT loci in these groups. Author summary Sexual development in fungi is governed by genes located within a single mating type (MAT) locus or at two unlinked MAT loci. While the latter is thought to be the ancestral state in basidiomycetes, physical linkage of the two MAT loci has occurred multiple times during basidiomycete evolution. Here, we show that physically linked MAT loci are present in all analyzed species of the basidiomycete order Trichosporonales. In contrast to previously studied basidiomycetes, the fused MAT loci in the Trichosporonales have highly conserved gene order, suggesting that this fusion might date back to the common ancestor of this lineage.

Mitochondrial genome of the basidiomycetous yeast Jaminaea angkorensis

Jaminaea angkorensis is an anamorphic basidiomycetous yeast species originally isolated from decaying leaves in Cambodia. Taxonomically, J. angkorensis is affiliated with Microstromatales (Exobasidiomycetes, Ustilaginomycotina, Basidiomycota) and represents a basal phylogenetic lineage of this fungal order. To perform a comparative analysis of J. angkorensis with other basidiomycetes, we determined and analyzed its complete mitochondrial DNA sequence. The mitochondrial genome is represented by 29,999 base pairs long, circular DNA containing 32 % guanine and cytosine residues. Its genetic organization is relatively compact and comprises typical genes for 15 conserved proteins involved in oxidative phosphorylation (atp6, 8, and 9; cob; cox1, 2, and 3; and nad1, 2, 3, 4, 4L, 5, and 6) and translation (rps3), two ribosomal RNAs (rnl and rns) and twenty-two transfer RNAs (trnA-Y). Although the gene content is similar to other basidiomycetes, the gene orders in the examined species exhibit only a limited synteny, reflecting their phylogenetic distances and extensive genome rearrangements. In addition, a comparative analysis of basidiomycete mitochondrial genomes indicates that stop-to-tryptophan reassignment of the UGA codon was accompanied by structural alterations of tRNA-Trp(CCA). These results provide an insight into the evolution of the genetic code in fungal mitochondria.