132 research outputs found
Ascospore discharge, germination and culture of fungal partners of tropical lichens, including the use of a novel culture technique
A total of 292 lichen samples, representing over 200 species and at least 65 genera and 26 families, were collected, mainly in Thailand; 170 of the specimens discharged ascospores in the laboratory. Generally, crustose lichens exhibited the highest discharge rates and percentage germination. In contrast, foliose lichen samples, although having a high discharge rate, had a lower percentage germination than crustose species tested. A correlation with season was indicated for a number of species. Continued development of germinated ascospores into recognizable colonies in pure culture was followed for a selection of species. The most successful medium tried was 2 % Malt-Yeast extract agar (MYA), and under static conditions using a liquid culture medium, a sponge proved to be the best of several physical carriers tested; this novel method has considerable potential for experimental work with lichen mycobionts
Salinomycin induces calpain and cytochrome c-mediated neuronal cell death
Salinomycin is a polyether antibiotic with properties of an ionophore, which is commonly used as cocciodiostatic drug and has been shown to be highly effective in the elimination of cancer stem cells (CSCs) both in vitro and in vivo. One important caveat for the potential clinical application of salinomycin is its marked neural and muscular toxicity. In the present study we show that salinomycin in concentrations effective against CSCs exerts profound toxicity towards both dorsal root ganglia as well as Schwann cells. This toxic effect is mediated by elevated cytosolic Na+ concentrations, which in turn cause an increase of cytosolic Ca2+ by means of Na+/Ca2+ exchangers (NCXs) in the plasma membrane as well as the mitochondria. Elevated Ca2+ then leads to calpain activation, which triggers caspase-dependent apoptosis involving caspases 12, 9 and 3. In addition, cytochrome c released from depolarized mitochondria directly activates caspase 9. Combined inhibition of calpain and the mitochondrial NCXs resulted in significantly decreased cytotoxicity and was comparable to caspase 3 inhibition. These findings improve our understanding of mechanisms involved in the pathogenesis of peripheral neuropathy and are important to devise strategies for the prevention of neurotoxic side effects induced by salinomycin
Diversity and Functional Traits of Lichens in Ultramafic Areas: A Literature Based Worldwide Analysis Integrated by Field Data at the Regional Scale
While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non-ultramafic substrates was conducted in Valle d’Aosta (North-West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity-difference-replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude-related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas
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A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families
The Lecanoromycetes is the largest class of lichenized Fungi, and one of the most species-rich classes in the
kingdom. Here we provide a multigene phylogenetic synthesis (using three ribosomal RNA-coding and two
protein-coding genes) of the Lecanoromycetes based on 642 newly generated and 3329 publicly available
sequences representing 1139 taxa, 317 genera, 66 families, 17 orders and five subclasses (four currently
recognized: Acarosporomycetidae, Lecanoromycetidae, Ostropomycetidae, Umbilicariomycetidae; and one provisionarily recognized, ‘Candelariomycetidae’). Maximum likelihood phylogenetic analyses on four
multigene datasets assembled using a cumulative supermatrix approach with a progressively higher
number of species and missing data (5-gene, 5 + 4-gene, 5 + 4 + 3-gene and 5 + 4 + 3 + 2-gene datasets)
show that the current classification includes non-monophyletic taxa at various ranks, which need to be
recircumscribed and require revisionary treatments based on denser taxon sampling and more loci. Two
newly circumscribed orders (Arctomiales and Hymeneliales in the Ostropomycetidae) and three families
(Ramboldiaceae and Psilolechiaceae in the Lecanorales, and Strangosporaceae in the Lecanoromycetes
inc. sed.) are introduced. The potential resurrection of the families Eigleraceae and Lopadiaceae is considered
here to alleviate phylogenetic and classification disparities. An overview of the photobionts associated
with the main fungal lineages in the Lecanoromycetes based on available published records is provided. A
revised schematic classification at the family level in the phylogenetic context of widely accepted and
newly revealed relationships across Lecanoromycetes is included. The cumulative addition of taxa with
an increasing amount of missing data (i.e., a cumulative supermatrix approach, starting with taxa for which
sequences were available for all five targeted genes and ending with the addition of taxa for which only two
genes have been sequenced) revealed relatively stable relationships for many families and orders.
However, the increasing number of taxa without the addition of more loci also resulted in an expected substantial
loss of phylogenetic resolving power and support (especially for deep phylogenetic relationships),
potentially including the misplacements of several taxa. Future phylogenetic analyses should include
additional single copy protein-coding markers in order to improve the tree of the Lecanoromycetes. As part
of this study, a new module (‘‘Hypha’’) of the freely available Mesquite software was developed to compare
and display the internodal support values derived from this cumulative supermatrix approach.Keywords: Classification, Multi-gene phylogeny, Lichenized fungi, Systematics, Cumulative supermatrix, Lecanoromycete
Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU
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Nieuwe Cladonia-soorten voor Nederland
Six new Cladoniae for the Netherlands are mentioned and their main characteristics described. Cladonia cenotea (Ach). Schaer., C. stellaris (Opiz) Pouzar et Vezda, C. subcervicornis (Vain.) DuRietz and C. symphycarpia Fik. are recorded from a single find. The first two were already labelled correctly, but not yet published. C. gonecha (Ach.) Asah. and C. rei Schaer. have been recognized by chemical methods from several localities, humous sites then C. rei seems to prefer less acid and less C. subulata (L.) Wigg., which closely resembles it
A Conspectus of the Lichens (Lichenized Fungi) of Singapore
Volume: 61Start Page: 437End Page: 48
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