An ontology of fungal subcellular traits.

UNLABELLED: • PREMISE OF THE STUDY: The Fungal Subcellular Ontology used in the Assembling the Fungal Tree of Life project is a taxon-wide ontology (controlled vocabulary for attributes) designed to clarify and integrate the broad range of subcellular characters and character states used in higher-level fungal systematics. As in the algae, cellular characters are important phylogenetic markers in kingdom Fungi. The Fungal Subcellular Ontology has been developed primarily to help researchers, especially systematists, in their search for information on subcellular characters across the Fungi, and it complements existing biological ontologies, including the Gene Ontology. • METHODS: The character and character state data set used in the Assembling the Fungal Tree of Life Structural and Biochemical Database (http://aftol.umn.edu) is the source of terms for generating the ontology. After the terms were accessioned and defined, they were combined in OBO-Edit file format, and the ontology was edited using OBO-Edit, an open source Java tool supported by the Gene Ontology project. • KEY RESULTS: The Fungal Subcellular Ontology covers both model and nonmodel fungi in great detail and is downloadable in OBO-Edit format at website http://aftol.umn.edu/ontology/fungal_subcellular.obo. • CONCLUSIONS: The ontology provides a controlled vocabulary of fungal subcellular terms and functions as an operating framework for the Assembling the Fungal Tree of Life Structural and Biochemical Database. An ontology-based design enhances reuse of data deposited in the Structural and Biochemical Database from other independent biological and genetic databases. Data integration approaches that advance access to data from the diversity of biological databases are imperative as interdisciplinary research gains importance. In this sense, the Fungal Subcellular Ontology becomes highly relevant to mycologists as well as nonmycologists because fungi interact actively as symbionts and parasites or passively with many other life forms.

Improved Microassays Used to Test Natural Product-Based and Conventional Fungicides on Plant Pathogenic Fungi.

Seven important plant pathogenic fungi (Botrytis cinerea, Colletotrichum acutatum, C. fragariae, C. gloeosporioides, Fusarium oxysporum, Phomopsis obscurans, and P. viticola) valuable in screening fungicides were tested. Our procedure included washing conidia to reduce germination times, incorporating Roswell Park Memorial Institute 1640 as a medium of known composition, and using coverslips in the 24-well cell culture clusters to document the effect of fungicides on fungal morphology. The natural product-based fungicide, sampangine, a sampangine analog, 4-bromosampangine, plus seven conventional fungicides (benomyl, captan, cyprodinil, fenbuconazole, fenhexamid, iprodione, and kresoxim-methyl) were tested in vitro for their ability to inhibit germination and growth of the seven fungal species. Sampangine inhibited germination in all fungi except C. acutatum. Comparison of results of germination and morphology microbioassays with results of microtiter assays suggests that some fungicides stop fungal germination, whereas others only slow down fungal growth. We hypothesize that sampangine, except against C. acutatum, has the same physical mode of action, germination inhibition, as the conventional fungicides captan, iprodione, and kresoxim-methyl. 4-Bromosampangine caused morphological anomalies including excessive branching of germ tubes of C. fragariae and splaying and branching of germ tubes of B. cinerea.

Large-scale polymeric carbon nanotube membranes with sub-1.27-nm pores.

We report the first characterization study of commercial prototype carbon nanotube (CNT) membranes consisting of sub-1.27-nm-diameter CNTs traversing a large-area nonporous polysulfone film. The membranes show rejection of NaCl and MgSO4 at higher ionic strengths than have previously been reported in CNT membranes, and specific size selectivity for analytes with diameters below 1.24 nm. The CNTs used in the membranes were arc discharge nanotubes with inner diameters of 0.67 to 1.27 nm. Water flow through the membranes was 1000 times higher than predicted by Hagen-Poiseuille flow, in agreement with previous CNT membrane studies. Ideal gas selectivity was found to deviate significantly from that predicted by both viscous and Knudsen flow, suggesting that surface diffusion effects may begin to dominate gas selectivity at this size scale.

Growth, feeding and reproduction of the catfish Eremophilus mutisii (Pisces: Trichomycteridae), from artificial reservoirs in Colombia.

The catfish, Eremophilus mutisii, was cultured under different densities in artificial rainfall reservoirs at Caldas, Boyacá, Colombia. At capture, the average total length of the animals was 10 cm and the weight ranged between 9 and 10 g. These fish were in initial stages of sexual development. After a year in the reservoirs, they had increased in length and weight as follows (densities in parentheses): 5.22 cm and 27.23 g (0.5 individuals/m2); 1.98 cm and 8.79 g (1 individual/m2), and 2.45 cm and 0.82 g (2 individuals/m2). They were at the early stages of sexual maturity, and their condition factor fluctuated between 0.61 and 0.96. They preferably ingested insect larvae that were found in benthic and littoral communities of the reservoirs. The benthos was dominated by ephippia of Daphnia, lumbriculids, and chironomid larvae. The biomass of benthic organisms ranged between 0.1126 and 1.3847 g/m2. In the littoral community aquatic insects were the most important component, especially the hemipterans. The biomass of the littoral fauna ranged between 0.14 and 4.05 g/m2.

Strawberry Anthracnose: Histopathology of Colletotrichum acutatum and C. fragariae.

ABSTRACT Ontogeny of the invasion process by Colletotrichum acutatum and C. fragariae was studied on petioles and stolons of the strawberry cultivar Chandler using light and electron microscopy. The invasion of host tissue by each fungal species was similar; however, each invasion event occurred more rapidly with C. fragariae than with C. acutatum. Following cuticular penetration via an appressorium, subsequent steps of invasion involved hyphal growth within the cuticle and within the cell walls of epidermal, subepidermal, and subtending cells. Both species of fungi began invasion with a brief biotrophic phase before entering an extended necrotrophic phase. Acervuli formed once the cortical tissue had been moderately disrupted and began with the development of a stroma just beneath the outer periclinal epidermal walls. Acervuli erupted through the cuticle and released conidia. Invasion of the vascular tissue typically occurred after acervulus maturation and remained minimal. Chitin distribution in walls of C. fragariae was visualized with gold-labeled wheat germ agglutinin. The outer layer of bilayered walls of conidia, germ tubes, and appressoria contained less chitin than unilayered hyphae in planta.

Phylogenetic distribution of fungal sterols.

BACKGROUND: Ergosterol has been considered the "fungal sterol" for almost 125 years; however, additional sterol data superimposed on a recent molecular phylogeny of kingdom Fungi reveals a different and more complex situation. METHODOLOGY/PRINCIPAL FINDINGS: The interpretation of sterol distribution data in a modern phylogenetic context indicates that there is a clear trend from cholesterol and other Delta(5) sterols in the earliest diverging fungal species to ergosterol in later diverging fungi. There are, however, deviations from this pattern in certain clades. Sterols of the diverse zoosporic and zygosporic forms exhibit structural diversity with cholesterol and 24-ethyl -Delta(5) sterols in zoosporic taxa, and 24-methyl sterols in zygosporic fungi. For example, each of the three monophyletic lineages of zygosporic fungi has distinctive major sterols, ergosterol in Mucorales, 22-dihydroergosterol in Dimargaritales, Harpellales, and Kickxellales (DHK clade), and 24-methyl cholesterol in Entomophthorales. Other departures from ergosterol as the dominant sterol include: 24-ethyl cholesterol in Glomeromycota, 24-ethyl cholest-7-enol and 24-ethyl-cholesta-7,24(28)-dienol in rust fungi, brassicasterol in Taphrinales and hypogeous pezizalean species, and cholesterol in Pneumocystis. CONCLUSIONS/SIGNIFICANCE: Five dominant end products of sterol biosynthesis (cholesterol, ergosterol, 24-methyl cholesterol, 24-ethyl cholesterol, brassicasterol), and intermediates in the formation of 24-ethyl cholesterol, are major sterols in 175 species of Fungi. Although most fungi in the most speciose clades have ergosterol as a major sterol, sterols are more varied than currently understood, and their distribution supports certain clades of Fungi in current fungal phylogenies. In addition to the intellectual importance of understanding evolution of sterol synthesis in fungi, there is practical importance because certain antifungal drugs (e.g., azoles) target reactions in the synthesis of ergosterol. These findings also invalidate use of ergosterol as an indicator of biomass of certain fungal taxa (e.g., Glomeromycota). Data from this study are available from the Assembling the Fungal Tree of Life (AFTOL) Structural and Biochemical Database: http://aftol.umn.edu.

Growth, feeding and reproduction of the catfish Eremophilus mutisii (Pisces: Trichomycteridae), from artificial reservoirs in Colombia

The catfish, Eremophilus mutisii, was cultured under different densities in artificial rainfall reservoirs at Caldas, Boyacá, Colombia. At capture, the average total length of the animals was 10 cm and the weight ranged between 9 and 10 g. These fish were in initial stages of sexual development. After a year in the reservoirs, they had increased in length and weight as follows (densities in parentheses): 5.22 cm and 27.23 g (0.5 individuals/m2); 1.98 cm and 8.79 g (1 individual/m2), and 2.45 cm and 0.82 g (2 individuals/m2). They were at the early stages of sexual maturity, and their condition factor fluctuated between 0.61 and 0.96. They preferably ingested insect larvae that were found in benthic and littoral communities of the reservoirs. The benthos was dominated by ephippia of Daphnia, lumbriculids, and chironomid larvae. The biomass of benthic organisms ranged between 0.1126 and 1.3847 g/m2. In the littoral community aquatic insects were the most important component, especially the hemipterans. The biomass of the littoral fauna ranged between 0.14 and 4.05 g/m2.

El “capitán de la sabana”, Eremophilus mutisii (Humboldt, 1805), fue cultivado en diferentes densidades en pequeños lagos artificiales localizados en Caldas, Boyacá, Colombia. Al inicio, el promedio de la longitud corporal fue 10 cm y el peso osciló entre 9 y 10 gr. Los peces se encontraban en estados iniciales de desarrollo sexual. Luego de un año de experimentación, los peces cultivados a una densidad de 0.5 ind/m2 incrementaron 5.22 cm en longitud y 27.23 gr en promedio (1 ind/m2: 1.98 cm y 8.79 gr; 2 ind/m2: 2.45 cm y 0.82 gr). Los peces se encontraban iniciando su madurez sexual, y su factor de condición fluctuó entre 0.61 y 0.96 y consumían principalmente larvas de insectos. El bentos estaba dominado por efipios de Daphnia, lumbricúlidos y larvas de quironómidos. La biomasa de organismos benticos osciló entre 0.1126 y 1.3847 gr/m2. En la comunidad litoral, los insectos acuáticos fueron los componentes mas importantes, especialmente los hemípteros. La biomasa de la fauna litoral osciló entre 0.14 y 4.05 gr/m2.