Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FUNGI”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1994

Protein secretion in filamentous fungi--trying to understand a highly productive black box.

Protein secretion is important in all fungi. The majority of proteins by fungi are thought to be glycosylated and many of them are structurally associated with the cell envelope, the plasma membrane and the cell wall. Many of the enzymes secreted by fungi have been incorporated into commercial processes and used in a range of industries. The existence of strains producing very high levels of secreted enzymes stimulated interest in the use of fungi as hosts for the expression of recombinant proteins. Despite the attention that protein secretion in fungi has attracted, and the multifaceted importance of the process, our understanding of the cellular mechanisms involved is still minimal and, for the most part, it is necessary to extrapolate from other eukaryotic organisms. However, current research suggests that protein secretion in filamentous fungi is intimately associated with the process of growth at the hyphal tip. Such unique features merit a detailed study of this important phenomenon.

Fungal Proteins↗
PubMed2005

Diversity of Salmonella spp. and fungi in northern Greek rivers and their correlation to fecal pollution indicators.

The prevalence and diversity of Salmonella spp., filamentous fungi, and yeasts and their correlation with fecal pollution indicators (total coliforms, fecal coliforms, enterococci) and total heterotrophic bacteria counts were investigated in 95 water samples from the northern Greek rivers Aliakmon and Axios. Salmonella spp. were isolated in 27.4% of the samples and a total of 19 serotypes were identified. The frequency of Salmonella isolation was higher in the Axios (36.8%) than in the Aliakmon (21.0%) river. Significantly (P<0.001) more Salmonella spp. were recovered during warm (41.4%) than cold (5.4%) months. Salmonella-positive samples showed significantly higher counts of total heterotrophic bacteria and coliforms. Filamentous fungi were isolated from 98.9% and yeasts from 17.9% of the samples with respective mean counts of 2.36 x 10(3) and 1.28 x 10(2)cfu/100mL. Totals of 23 genera of filamentous fungi and 3 genera of yeasts were identified. The most frequent filamentous fungi were Penicillium and Aspergillus, while Candida was the most prevalent yeast. A significant (P<0.001) positive correlation of the fecal pollution indicators was demonstrated only for filamentous fungi. The results of this study indicate that these rivers may be potential pathways for human and other animal contamination with Salmonella spp., filamentous fungi, and yeasts, which contribute to the pollution of marine waters and the surrounding environment.

Colony Count, Microbial↗
PubMed2006

Molecular evidence of fungal signatures in the marine protist Corallochytrium limacisporum and its implications in the evolution of animals and fungi.

Fungi, animals, and single-celled organisms belonging to the choanozoans together constitute the supergroup Opisthokonta. The latter are considered crucial in understanding the evolutionary origin of animals and fungi. The choanozoan Corallochytrium limacisporum is an enigmatic marine protist of considerable interest in opisthokontan evolution. Several isolates of the organism were obtained from a coral reef lagoon in the Lakshadweep group of islands of the Arabian Sea. The capability of these cultures to grow on media containing inorganic nitrogen sources prompted us to examine the possible presence of fungal signatures, namely the enzyme alpha-aminoadipate reductase (alpha-AAR) involved in the alpha-aminoadipate (AAA) pathway for synthesizing lysine and ergosterol, in one of the isolates. These features, as well as the sterol C-14 reductase gene involved in the sterol pathway of animals and fungi, were detected in the organism. Phylogenetic trees based on the alpha-AAR gene suggested that Corallochytrium limacisporum is a sister clade to fungi, while those based on the C-14 reductase gene did not adequately resolve whether the organism was more closely related to fungi or animals. While many studies indicate that Corallochytrium is a sister clade to animals, we suggest that further studies are required to examine whether this protist is in fact more closely related to fungi rather than to animals.

Animals↗
PubMed2004

Fungi ingestion as an important factor influencing heavy metal intake in roe deer: evidence from faeces.

In nature, animals have to cope with the fluctuating bioavailable metal pool in their habitat, which results in a seasonal variability of heavy metal levels in the animal body. Indeed, a pronounced summer-autumnal peak of heavy metals in roe deer (Capreolus capreolus L.) kidney was recently found in Slovenia. Considering the well-known hyperaccumulative ability of fungi, their ingestion was hypothesised to be one of the main reasons for the peak. Although fungi as a group are known to be a seasonally important food source for roe deer, data on their composition in the nutrition of the species have been lacking. To ascertain the importance of fungi ingestion on heavy metal intake in roe deer, we simultaneously studied fungal spores (by microscopic determination) and heavy metal levels (by inductively coupled plasma mass spectrometry and atomic absorption spectrometry) in roe deer faeces, collected in the period July-November 2001 at Veliki Vrh, the Salek Valley, Slovenia. Irrespective of species, fungal spores were present in 89% of faeces; the following genera were found to be consumed by roe deer: Lycoperdon, Calvatia, Hypholoma, Coprinus, Russula, Elaphomyces, Xerocomus, Enteloma, Amanita, Cortinarius, Agaricus, Inocybe, Boletus, Macrolepiota, Suillus and Pluteus. While the importance of fungi ingestion on the seasonal variability of other metals is less clear, it doubtless influences Hg intake in roe deer, which is confirmed by: (a) the high frequency of fungi in roe deer nutrition; (b) their hyperaccumulative ability; (c) the temporal distribution of Hg in roe deer faeces; (d) differences among three classes of faeces established on the basis of the frequency of spores present; (e) the correlation between the number of fungal genera present and Hg levels in faeces. Therefore, the influence of fungi ingestion has to be taken into consideration in assessing the hazard due to the accumulation of mercury along the food-chain.

Animals↗
PubMed1997

Enumeration of fungi in barley.

Estimation of fungal contamination of barley grain is important as certain fungi can proliferate during the malting process. The following factors which may affect the enumeration of fungi were evaluated: dilution versus direct plating, presoaked versus unsoaked grain, five culture media: potato dextrose agar (PDA), acidified Czapek-Dox agar (ACA), pentachloronitrobenzene agar; (PCNB) dichloran rose bengal chloramphenicol agar (DRBC) and malt salt agar; two disinfectants' ethanol/water (80:20 v/v) and sodium hypochlorite (3.5% w/v in H2O). Two barley samples, one having a high incidence of storage fungi and one with a high incidence of field fungi were used and most fungi were identified to species level. Results showed that direct plating was superior to dilution plating for assessing the mycoflora of barley. Unsoaked grain gave significantly higher counts than presoaked grain in the case of Alternaria alternata, Rhizopus oryzae, Epicoccum nigrum and Mucor spp. Presoaked grain resulted in higher counts of Penicillium spp. Chlorine disinfection resulted in significantly higher counts of Aspergillus flavus, Eurotium spp. and Penicillium spp. Ethanol disinfection resulted in higher counts of Mucor spp., Phoma sorghina, Rhizopus oryzae and Aspergillus restrictus. PDA and ACA, in general gave some what better results than DRBC for both field and storage fungi. PCNB consistently gave the highest Fusarium counts. More than thiry fungal genera were found in the two samples.

Agar↗
PubMed2003

Biosynthesis of fungal melanins and their importance for human pathogenic fungi.

For more than 40 years fungi have been known to produce pigments known as melanins. Predominantly these have been dihydroxyphenylalanine (DOPA)-melanin and dihydroxynaphthalene (DHN)-melanin. The biochemical and genetical analysis of the biosynthesis pathways have led to the identification of the genes and corresponding enzymes of the pathways. Only recently have both these types of melanin been linked to virulence in some human pathogenic and phytopathogenic fungi. The absence of melanin in human pathogenic and phytopathogenic fungi often leads to a decrease in virulence. In phytopathogenic fungi such as Magnaporthe grisea and Colletotrichum lagenarium, besides other possible functions in pathogenicity, DHN-melanin plays an essential role in generating turgor for plant appressoria to penetrate plant leaves. While the function of melanin in human pathogenic fungi such as Cryptococcus neoformans, Wangiella dermatitidis, Sporothrix schenckii, and Aspergillus fumigatus is less well defined, its role in protecting fungal cells has clearly been shown. Specifically, the ability of both DOPA- and DHN-melanins to quench free radicals is thought to be an important factor in virulence. In addition, in several fungi the production of fungal virulence factors, such as melanin, has been linked to a cAMP-dependent signaling pathway. Many of the components involved in the signaling pathway have been identified.

Cryptococcus neoformans↗
PubMed2005

[Endophytic fungi in rose (Rosa hybrida) in Bogota, Colombia].

We have investigated the presence of endophytic fungi associated with rose plants (Rosa hybrida) in Colombia. Endophytic fungi were isolated from healthy leaves of ten ornamental roses plants from gardens cultured in malt extract, peptone, yeast extract agar plates (MPY). We sampled 560 leaves fragments, 56 per sample. Endophytic fungi comprised 92 isolates (16.4%); of these isolates, 41 were classified as sterile mycelium (without reproductive structures that allowed their identification), 31 isolates were identified to genus or to species, and 20 isolates could not be identified at all. The identified endophytic fungi were as follow: Nigrospora oryzae, Aureobasidium spp, Acremonium spp. The fungi Nodulisporium sp, Gliocladium virens, Cladosporium sp, Alternaria sp, Phoma sp and Chaetomium globosum were represented by one isolate each. Since the endophytic fungi are known for their capacity to produce metabolites with biological activity, it is possible that the microorganisms found in this study have potential as antagonist of rose pathogens.

Colombia↗
PubMed2003

Interactions between nematophagous fungi and consequences for their potential as biological agents for the control of potato cyst nematodes.

The efficacies of three nematophagous fungi, Paecilomyces lilacinus, Plectosphaerella cucumerina and Pochonia chlamydosporia, for controlling potato cyst nematodes (PCN) as part of an Integrated Pest Management (IPM) regime were studied. The compatibility of the nematophagous fungi with commonly used chemical pesticides and their ability to compete with the soil fungi Rhizoctonia solani, Chaetomium globosum, Fusarium oxysporum, Penicillium bilaii and Trichoderma harzianum were tested in vitro. Paecilomyces lilacinus was the most successful competitor when the ability to grow and inhibit growth of an opposing colony at both 10 and 20 degrees C was considered. P. lilacinus also showed potential for control of the soil-borne fungal pathogen R. solani, releasing a diffusable substance in vitro which inhibited its growth and caused morphological abnormalities in its hyphae. Pochonia chlamydosporia was least susceptible to growth inhibition by other fungi at 20 degrees in vitro, but the isolate tested did not grow at 10 degrees. Plectosphaerella cucumerina was a poor saprophytic competitor. Radial growth of Paecilomyces lilacinus and Plectosphaerella cucumerina was slowed, but not prevented, when grown on potato dextrose agar incorporating the fungicides fenpiclonil and tolclofos-methyl, and was not inhibited by the addition of pencycuron or the nematicide oxamyl. Radial growth of Pochonia chlamydosporia was partially inhibited by all the chemical pesticides tested. The efficacy of Paecilomyces lilacinus as a control agent for R. solani was further investigated in situ. Treatment with P. lilacinus significantly reduced the symptoms of Rhizoctonia disease on potato stems in a pot trial. The effectiveness of P. lilacinus and P. cucumerina against PCN was also tested in situ. Three application methods were compared; incorporating the fungi into alginate pellets, Terra-Green inoculated with the fungi and applying conidia directly to the tubers. Both formulations containing P. lilacinus and formulation mixtures alone, particularly alginate pellets, significantly reduced multiplication of PCN in soil. We conclude that P. lilacinus showed the greatest potential for use in combination with selected fungicides and nematicides as part of an IPM programme for the control of PCN, but further work is required to confirm whether it is effective against PCN in soil.

Animals↗
PubMed2004

Removal of monomeric phenols in dry mill olive residue by saprobic fungi.

The dry olive residue (DOR) obtained from the olive oil extraction process has toxic components against plants and microorganism growth, particularly monomeric phenols. In this investigation nine saprobic fungi were found to be capable of completely removing these phenols from the solid after 20 weeks of growth, although the rate depended on the type of fungi and phenol. Results showed that most of the fungi tested first eliminated o-diphenols and then non-o-diphenols. However, some fungi did not follow this trend. Phanerochaete chrysosporium first removed hydroxytyrosol and tyrosol and later their glucosides and, in contrast, Paecylomyces farinosus hydrolyzed hydroxytyrosol and tyrosol glucosides at the first stage, 2 weeks of growth, and then eliminated all monomeric phenols. The behavior of this fungus seems of great interest for recovering phenolic antioxidants from the DOR. Similarly, differences in DOR decolorization capacity among the fungi tested were also observed. Coriolopsis rigida showed the highest capacity, followed by Phebia radiata, Pycnoporus cinnabarinus, and Pha. chrysosporium. Therefore, both decolorization and monomeric phenol elimination pointed out that saprobic fungi could be used to detoxify the DOR obtained from the two-phase system of the olive oil extraction process.

Food Handling↗
PubMed1998

Temperature and NaCl-tolerance of rock-inhabiting meristematic fungi.

Black meristematic fungi together with lichens and cyanobacteria dominate the micro-flora of rock surfaces in arid and semi-arid environments of hot and cold deserts. This study shows that rock inhabiting meristematic fungi are extremely tolerant against high temperatures, desiccation and osmotic stress. Their temperature tolerance increases with increasing dehydration of the fungal thallus. Air dried mycelia of black yeasts stand temperatures up to 120 degrees C for at least 0.5 hours. As response to high temperatures multilayered cell walls are developed and trehalose is accumulated whereas the intracellular glycerol regulates the osmotic potential under NaCl stress. Strains from rock in moderate climate (North Germany) show the same tolerance than those isolated from the Mediterranean area. Hortaea werneckii--hitherto only described as agent of human Tinea nigra--is shown to be the most tolerant rock inhabiting species tested. Meristematic fungi cannot be pre-adapted to higher growth temperatures by increased incubation temperatures. Considering the results of this study the justification of the term 'stress' is discussed with regard to rock inhabiting fungi and their natural environment. Consequences for conservation treatments of monuments decayed by meristematic fungi are discussed on the basis of the ecophysiological properties of the fungi.

Desiccation↗
PubMed2002

Epiparasitic plants specialized on arbuscular mycorrhizal fungi.

Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature.

Argentina↗
PubMed1998

Characterization of root colonization profiles by a microcosm community of arbuscular mycorrhizal fungi using 25S rDNA-targeted nested PCR.

The aim of the present work was to study colonization patterns in roots by different arbuscular mycorrhizal fungi developing from a mixed community in soil. As different fungi cannot be distinguished with certainty in planta on the basis of fungal structures, taxon-discriminating molecular probes were developed. The 5' end of the large ribosomal subunit containing the variable domains D1 and D2 was amplified by PCR from Glomus mosseae (BEG12), G. intraradices (LPA8), Gigaspora rosea (BEG9) and Scutellospora castanea (BEG1) using newly designed eukaryote-specific primers. Sequences of the amplification products showed high interspecies variability and PCR taxon-discriminating primers were designed to distinguish between each of these four fungi. A nested PCR, using universal eukaryotic primers for the first amplification and taxon-discriminating primers for the second, was performed on individual trypan blue-stained mycorrhizal root fragments of onion and leek, and root colonization by four fungi inoculated together in a microcosm experiment was estimated. More than one fungus was detected in the majority of root fragments and all four fungi frequently co-existed within the same root fragment. Root colonization by G. mosseae and G. intraradices was similar from individual mixed inoculum, whilst the frequency of S. castanea and Gig. rosea increased in the presence of the two Glomus species, suggesting that synergistic interactions may exist between some arbuscular mycorrhizal fungi.

Allium↗
PubMed2001

Recovery of filamentous fungi from water in a paediatric bone marrow transplantation unit.

In order to determine whether water or water-related surfaces are a reservoir for opportunistic filamentous fungi, water sampling in the paediatric bone marrow transplantation (BMT) unit of the National Hospital University of Oslo, Norway was performed. During a six-month period 168 water samples and 20 samples from water-related surfaces were taken. The water samples were taken from the taps and showers in the BMT unit and from the main pipe supplying the paediatric department with water. In addition, 20 water samples were taken at the intake reservoir supplying the city of Oslo with drinking water. Filamentous fungi were recovered from 94% of all the water samples taken inside the hospital with a mean colony forming unit (cfu) count of 2.7/500mL of water. Aspergillus fumigatus was recovered from 49% and 5.6% of water samples from the taps and showers, respectively (mean 1.9 and 1.0cfu/500mL). More than one third (38.8%) of water samples from the main pipe revealed A. fumigatus (mean 2.1cfu/500mL). All water samples taken at the intake reservoir were culture positive for filamentous fungi, 85% of the water samples showed A. fumigatus (mean 3.1cfu/500mL). Twenty-five percent of water-related surfaces yielded filamentous fungi, but A. fumigatus was recovered from only two samples. We showed that filamentous fungi are present in the hospital water and to a lesser extent on water-related surfaces. The recovery of filamentous fungi in water samples taken at the intake reservoir suggests that the source of contamination is located outside the hospital.

Air Microbiology↗
PubMedDate not supplied

Changes in airborne fungi from the outdoors to indoor air; large HVAC systems in nonproblem buildings in two different climates.

Little is known about the changes in occurrence and distribution of airborne fungi as they are transported in the airstream from the outdoor air through the heating, ventilation, and air conditioning (HVAC) system to the indoor air. To better understand this, airborne fungi were analyzed in the HVAC systems of two large office buildings in different climate zones. Fungal samples were taken in each of the walk-in chambers of the HVAC systems using a six-stage Andersen Sampler with malt extract agar. Results showed that fungal species changed with different locations in the HVAC systems. The outdoor air intake produced the greatest filtration effect for both the counts and species of outdoor air fungi. The colony forming unit (CFU) counts and species diversity was further reduced in the air directly after the filters. The cooling coils also had a substantial filtration effect. However, in room air the CFU counts were double and the mixture of fungal species was different from the air leaving the HVAC system at the supply air outlet in most locations. Diffusion of outdoor air fungi to the indoors did not explain the changes in the mixture of airborne fungi from the outdoor air to the indoor air, and some of the fungi present in the indoor air did not appear to be transported indoors by the HVAC systems.

Air Conditioning↗
PubMed2006

Filamentous fungi in a tertiary care hospital: environmental surveillance and susceptibility to antifungal drugs.

OBJECTIVE: To evaluate filamentous fungi with respect to environmental load and potential drug resistance in a tertiary care teaching hospital. DESIGN: Monthly survey in 2 buildings of the hospital during a 12-month period. SETTING: Hippokration Hospital in Thessaloniki, Greece. METHODS: Air, surface, and tap water sampling was performed in 4 departments with high-risk patients. As sampling sites, the solid-organ transplantation department and the hematology department (in the older building) and the pediatric oncology department and the pediatric intensive care unit (in the newer building) were selected. RESULTS: From January to May of 2000, the fungal load in air (FLA) was low, ranging from 0 to 12 colony-forming units (cfu) per m(3) in both buildings. During the summer months, when high temperature and humidity predominate, the FLA increased to 4-56 cfu/m(3). The fungi commonly recovered from culture of air specimens were Aspergillus niger (25.9%), Aspergillus flavus (17.7%), and Aspergillus fumigatus (12.4%). Non-Aspergillus filamentous fungi, such as Zygomycetes and Dematiaceous species, were also recovered. The pediatric intensive care unit had the lowest mean FLA (7.7 cfu/m(3)), compared with the pediatric oncology department (8.7 cfu/m(3)), the solid-organ transplantation department (16.1 cfu/m(3)), and the hematology department (22.6 cfu/m(3)). Environmental surfaces were swabbed, and 62.7% of the swab samples cultured yielded filamentous fungi similar to the fungi recovered from air but with low numbers of colony-forming units. Despite vigorous sampling, culture of tap water yielded no fungi. The increase in FLA observed during the summer coincided with renovation in the building that housed the solid-organ transplantation and hematology departments. All 54 Aspergillus air isolates randomly selected exhibited relatively low minimum inhibitory or effective concentrations for amphotericin B, itraconazole, voriconazole, posaconazole, micafungin, and anidulafungin. CONCLUSION: Air and surface fungal loads may vary in different departments of the same hospital, especially during months when the temperature and humidity are high. Environmental Aspergillus isolates are characterized by lack of resistance to clinically important antifungal agents.

Air Microbiology↗
PubMed2002

Effect of sampling time on the culturability of airborne fungi and bacteria sampled by filtration.

Air sampling of bioaerosols by filtration may be preferable for many epidemiological studies because the methods can be used to collect personal samples for a full work-shift. There is some concern, however, that the viability of fungal spores and bacterial cells might be compromised by sampling for as long as a full shift. This study was designed to determine the effect of sampling up to 6 h on the viability (measured by culture) of airborne fungi and bacteria at composting facilities. Six side-by-side samples were collected in two locations at each of three composting facilities for 1 h at 2 l/m on polycarbonate filters. Two samples in each set were then capped while clean, HEPA-filtered air was drawn across two others for an additional 2 h and across the last two for an additional 5 h. Filters were washed and the samples were analyzed for culturable bacteria and fungi, and for total bacteria and fungi by microscopic counting. Concentrations ranged from 1.7 x 10(3) to 6.2 x 10(7) c.f.u./m3 of culturable fungi and 1.17 x 10(4) to 1.0 x 10(6) c.f.u./m3 of culturable bacteria. In linear models that included duration of sampling, location, and the interaction of location and sample duration, neither sample duration nor the interaction term were significant predictors of the logs of the concentrations of culturable fungi or bacteria or of the ratio of the logs of the culturable concentrations to total concentrations for fungi or bacteria. This suggests that increased sampling time does not affect the viability of the organisms commonly found in the air at composting facilities.

Air Microbiology↗
PubMed2004

A functional screen identifies lateral transfer of beta-glucuronidase (gus) from bacteria to fungi.

Lateral gene transfer (LGT) from prokaryotes to microbial eukaryotes is usually detected by chance through genome-sequencing projects. Here, we explore a different, hypothesis-driven approach. We show that the fitness advantage associated with the transferred gene, typically invoked only in retrospect, can be used to design a functional screen capable of identifying postulated LGT cases. We hypothesized that beta-glucuronidase (gus) genes may be prone to LGT from bacteria to fungi (thought to lack gus) because this would enable fungi to utilize glucuronides in vertebrate urine as a carbon source. Using an enrichment procedure based on a glucose-releasing glucuronide analog (cellobiouronic acid), we isolated two gus(+) ascomycete fungi from soils (Penicillium canescens and Scopulariopsis sp.). A phylogenetic analysis suggested that their gus genes, as well as the gus genes identified in genomic sequences of the ascomycetes Aspergillus nidulans and Gibberella zeae, had been introgressed laterally from high-GC gram(+) bacteria. Two such bacteria (Arthrobacter spp.), isolated together with the gus(+) fungi, appeared to be the descendants of a bacterial donor organism from which gus had been transferred to fungi. This scenario was independently supported by similar substrate affinities of the encoded beta-glucuronidases, the absence of introns from fungal gus genes, and the similarity between the signal peptide-encoding 5' extensions of some fungal gus genes and the Arthrobacter sequences upstream of gus. Differences in the sequences of the fungal 5' extensions suggested at least two separate introgression events after the divergence of the two main Euascomycete classes. We suggest that deposition of glucuronides on soils as a result of the colonization of land by vertebrates may have favored LGT of gus from bacteria to fungi in soils.

Amino Acid Sequence↗
PubMed2005

The protistan origins of animals and fungi.

Recent molecular studies suggest that Opisthokonta, the eukaryotic supergroup including animals and fungi, should be expanded to include a diverse collection of primitively single-celled eukaryotes previously classified as Protozoa. These taxa include corallochytreans, nucleariids, ministeriids, choanoflagellates, and ichthyosporeans. Assignment of many of these taxa to Opisthokonta remains uncorroborated as it is based solely on small subunit ribosomal RNA trees lacking resolution and significant bootstrap support for critical nodes. Therefore, important details of the phylogenetic relationships of these putative opisthokonts with each other and with animals and fungi remain unclear. We have sequenced elongation factor 1-alpha (EF-1alpha), actin, beta-tubulin, and HSP70, and/or alpha-tubulin from representatives of each of the proposed protistan opisthokont lineages, constituting the first protein-coding gene data for some of them. Our results show that members of all opisthokont protist groups encode a approximately 12-amino acid insertion in EF-1alpha, previously found exclusively in animals and fungi. Phylogenetic analyses of combined multigene data sets including a diverse set of opisthokont and nonopisthokont taxa place all of the proposed opisthokont protists unequivocally in an exclusive clade with animals and fungi. Within this clade, the nucleariid appears as the closest sister taxon to fungi, while the corallochytrean and ichthyosporean form a group which, together with the ministeriid and choanoflagellates, form two to three separate sister lineages to animals. These results further establish Opisthokonta as a bona fide taxonomic group and suggest that any further testing of the legitimacy of this taxon should, at the least, include data from opisthokont protists. Our results also underline the critical position of these "animal-fungal allies" with respect to the origin and early evolution of animals and fungi.

Actins↗