210 research outputs found
Phylogenetic diversity of insecticolous fusaria inferred from multilocus DNA sequence data and their molecular identification via FUSARIUM-ID and Fusarium MLST
We constructed several multilocus DNA sequence datasets to assess the phylogenetic diversity of insecticolous fusaria, especially focusing on those housed at the Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF), and to aid molecular identifications of unknowns via the FUSARIUM-ID and Fusarium MLST online databases and analysis packages. Analyses of a 190-taxon, two-locus dataset, which included 159 isolates from insects, indicated that: (i) insect-associated fusaria were nested within 10 species complexes spanning the phylogenetic breadth of Fusarium, (ii) novel, putatively unnamed insecticolous species were nested within 8/10 species complexes and (iii) Latin binomials could be applied with confidence to only 18/58 phylogenetically distinct fusaria associated with pest insects. Phylogenetic analyses of an 82-taxon, three-locus dataset nearly fully resolved evolutionary relationships among the 10 clades containing insecticolous fusaria. Multilocus typing of isolates within four species complexes identified surprisingly high genetic diversity in that 63/65 of the fusaria typed represented newly discovered haplotypes. The DNA sequence data, together with corrected ABI sequence chromatograms and alignments, have been uploaded to the following websites dedicated to identifying fusaria: FUSARIUM-ID (http://isolate.fusariumdb.org) a
Evaluating different storage media for identification of Taenia saginata proglottids using MALDI-TOF mass spectrometry
Taenia saginata is a helminth that can cause taeniasis in humans and cysticercosis in cattle. A species-specific diagnosis and differentiation from related species (e.g., Taenia solium) is crucial for individual patient management and disease control programs. Diagnostic stool microscopy is limited by low sensitivity and does not allow discrimination between T. saginata and T. solium. Molecular diagnostic approaches are not routinely available outside research laboratories. Recently, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) was proposed as a potentially suitable technique for species-specific helminth diagnosis. However, standardized protocols and commercial databases for parasite identification are currently unavailable, and pre-analytical factors have not yet been assessed. The purpose of this study was to employ MALDI-TOF MS for the identification of T. saginata proglottids obtained from a human patient, and to assess the effects of different sample storage media on the technique's diagnostic accuracy. We generated T. saginata-specific main spectral profiles and added them to an in-house database for MALDI-TOF MS-based diagnosis of different helminths. Based on protein spectra, T. saginata proglottids could be successfully differentiated from other helminths, as well as bacteria and fungi. Additionally, we analyzed T. saginata proglottids stored in (i) LC-MS grade water; (ii) 0.45% sodium chloride; (iii) 70% ethanol; and (iv) 37% formalin after 2, 4, 6, 8, 12, and 24 weeks of storage. MALDI-TOF MS correctly identified 97.2-99.7% of samples stored in water, sodium chloride, and ethanol, with log-score values ≥2.5, thus indicating reliable species identification. In contrast, no protein spectra were obtained for samples stored in formalin. We conclude that MALDI-TOF-MS can be successfully employed for the identification of T. saginata, and that water, sodium chloride, and ethanol are equally effective storage solutions for prolonged periods of at least 24 weeks. © 2021 by the authors. Licensee MDPI, Basel, Switzerlan
Comparative genomics of Beauveria bassiana: uncovering signatures of virulence against mosquitoes
Fungal chitinases: diversity, mechanistic properties and biotechnological potential
Chitin derivatives, chitosan and substituted chito-oligosaccharides have a wide spectrum of applications ranging from medicine to cosmetics and dietary supplements. With advancing knowledge about the substrate-binding properties of chitinases, enzyme-based production of these biotechnologically relevant sugars from biological resources is becoming increasingly interesting. Fungi have high numbers of glycoside hydrolase family 18 chitinases with different substrate-binding site architectures. As presented in this review, the large diversity of fungal chitinases is an interesting starting point for protein engineering. In this review, recent data about the architecture of the substrate-binding clefts of fungal chitinases, in connection with their hydrolytic and transglycolytic abilities, and the development of chitinase inhibitors are summarized. Furthermore, the biological functions of chitinases, chitin and chitosan utilization by fungi, and the effects of these aspects on biotechnological applications, including protein overexpression and autolysis during industrial processes, are discussed in this review
Habitat and Host Indicate Lineage Identity in Colletotrichum gloeosporioides s.l. from Wild and Agricultural Landscapes in North America
Understanding the factors that drive the evolution of pathogenic fungi is central to revealing the mechanisms of virulence and host preference, as well as developing effective disease control measures. Prerequisite to these pursuits is the accurate delimitation of species boundaries. Colletotrichum gloeosporioides s.l. is a species complex of plant pathogens and endophytic fungi for which reliable species recognition has only recently become possible through a multi-locus phylogenetic approach. By adopting an intensive regional sampling strategy encompassing multiple hosts within and beyond agricultural zones associated with cranberry (Vaccinium macrocarpon Aiton), we have integrated North America strains of Colletotrichum gloeosporioides s.l. from these habitats into a broader phylogenetic framework. We delimit species on the basis of genealogical concordance phylogenetic species recognition (GCPSR) and quantitatively assess the monophyly of delimited species at each of four nuclear loci and in the combined data set with the genealogical sorting index (gsi). Our analysis resolved two principal lineages within the species complex. Strains isolated from cranberry and sympatric host plants are distributed across both of these lineages and belong to seven distinct species or terminal clades. Strains isolated from V. macrocarpon in commercial cranberry beds belong to four species, three of which are described here as new. Another species, C. rhexiae Ellis & Everh., is epitypified. Intensive regional sampling has revealed a combination of factors, including the host species from which a strain has been isolated, the host organ of origin, and the habitat of the host species, as useful indicators of species identity in the sampled regions. We have identified three broadly distributed temperate species, C. fructivorum, C. rhexiae, and C. nupharicola, that could be useful for understanding the microevolutionary forces that may lead to species divergence in this important complex of endophytes and plant pathogens
Optical Light Curves of the Type Ia Supernovae 1990N and 1991T
We present UBVRI light curves for the bright Type Ia supernovae SN 1990N in
NGC 4639 and SN 1991T in NGC 4527 based on photometry gathered in the course of
the Calan/Tololo supernova program. Both objects have well-sampled light curves
starting several days before maximum light and spanning well through the
exponential tail. These data supercede the preliminary photometry published by
Leibundgut et al (1991) and Phillips et al (1992). The host galaxies for these
supernovae have (or will have) accurate distances based on the Cepheid
period-luminosity relationship. The photometric data in this paper provide
template curves for the study of general population of Type Ia supernova and
accurate photometric indices needed for the Cepheid-supernova distance scale.Comment: AAS LaTeX, 30 pages, 10 figures, to appear in the Jan 1998
Astronomical Journal. Figs 1 and 2 (finding charts) not include
The Evolution of Invasiveness in Garden Ants
It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects
Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs
A new pleosporalean family Tetraplosphaeriaceae is established to
accommodate five new genera; 1) Tetraplosphaeria with small ascomata
and anamorphs belonging to Tetraploa s. str., 2)
Triplosphaeria characterised by hemispherical ascomata with rim-like
side walls and anamorphs similar to Tetraploa but with three conidial
setose appendages, 3) Polyplosphaeria with large ascomata surrounded
by brown hyphae and anamorphs producing globose conidia with several setose
appendages, 4) Pseudotetraploa, an anamorphic genus, having
obpyriform conidia with pseudosepta and four to eight setose appendages, and
5) Quadricrura, an anamorphic genus, having globose conidia with one
or two long setose appendages at the apex and four to five short setose
appendages at the base. Fifteen new taxa in these genera mostly collected from
bamboo are described and illustrated. They are linked by their Tetraploa
s. l. anamorphs. To infer phylogenetic placement in the
Pleosporales, analyses based on a combined dataset of small- and
large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out.
Tetraplosphaeriaceae, however, is basal to the main pleosporalean
clade and therefore its relationship with other existing families was not
completely resolved. To evaluate the validity of each taxon and to clarify the
phylogenetic relationships within this family, further analyses using
sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α
(TEF), and β-tubulin (BT), were also conducted. Monophyly of the family
and that of each genus were strongly supported by analyses based on a combined
dataset of the three regions (ITS+TEF+BT). Our results also suggest that
Tetraplosphaeria (anamorph: Tetraploa s. str.) is an
ancestral lineage within this family. Taxonomic placement of the bambusicolous
fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina,
Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and
Versicolorisporium, are also discussed based on the SSU+LSU
phylogeny
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