Flippase (FLP) recombinase-mediated marker recycling in the dermatophyte Arthroderma vanbreuseghemii.

Biological processes can be elucidated by investigating complex networks of relevant factors and genes. However, this is not possible in species for which dominant selectable markers for genetic studies are unavailable. To overcome the limitation in selectable markers for the dermatophyte Arthroderma vanbreuseghemii (anamorph: Trichophyton mentagrophytes), we adapted the flippase (FLP) recombinase-recombination target (FRT) site-specific recombination system from the yeast Saccharomyces cerevisiae as a selectable marker recycling system for this fungus.

Activation of beta-glucan synthases by wall-bound purple acid phosphatase in tobacco cells.

Wall-bound purple acid phosphatases have been shown to be potentially involved in the regulation of plant cell growth. The aim of this work was to further investigate the function of one of these phosphatases in tobacco (Nicotiana tabacum), NtPAP12, using transgenic cells overexpressing the enzyme. The transgenic cells exhibited a higher level of phosphatase activity in their walls.

pfaB products determine the molecular species produced in bacterial polyunsaturated fatty acid biosynthesis.

When pDHA4, a vector carrying all five pfaA-pfaE genes responsible for docosahexaenoic acid (DHA; 22:6) biosynthesis in Moritella marina MP-1, was coexpressed in Escherichia coli with the individual pfaA-pfaD genes for eicosapentaenoic acid (EPA; 20:5) biosynthesis from Shewanella pneumatophori SCRC-2738, both polyunsaturated fatty acids were synthesized only in the recombinant carrying pfaB for EPA synthesis. Escherichia coli coexpressing a deleted construct comprising pfaA, pfaC, pfaD and pfaE for EPA and pfaB for DHA produced EPA and DHA. Both EPA and DHA were detected in bacteria that inherently contained pfa genes for DHA.

Isolation and characterization of a novel thraustochytrid-like microorganism that efficiently produces docosahexaenoic acid.

A thraustochytrid-like microorganism (strain 12B) was isolated from the mangrove area of Okinawa, Japan. On the basis of its ectoplasmic net structure and biflagellate zoospores we determined strain 12B to be a novel member of the phylum Labyrinthulomycota in the kingdom Protoctista. When grown on glucose/seawater at 28 degrees C, it had a lipid content of 58% with docosahexaenoic acid (DHA; 22:6 n-3) at 43% of the total fatty acids.

Vital growth factors of Malassezia species on modified CHROMagar Candida.

A comparison of several media, i.e., potato dextrose agar with olive oil (Oil-PDA), modified Dixon agar (mDIX) and variations of Leeming and Notman agar (LNA) for the isolation and growth of Malassezia and Candida species was examined.

Comparative evaluation of standard dilution method and commercial kit for frozen plate antifungal susceptibility testing of yeasts using 200 clinical isolates.

A comparative evaluation of standard microdilution methods and a commercial kit for frozen plate antifungal susceptibility testing of yeasts was performed using amphotericin B, flucytosine, fluconazole, miconazole, and itraconazole on 200 yeast isolates. The isolates included 100 strains of Candida albicans, eight of C. tropicalis, twelve of C.

Cell shape regulation and co-translocation of actin and adenosyl homocysteinase in response to intermediate hypertonicity.

Hypertonic stimulation induced association of S-adenosyl-L-homocysteine hydrolase (SAHH) with the F-actin-rich cell cortex in Dictyostelium. At intermediate, but not higher, levels of hypertonicity, SAHH further translocated from the cortex to the cytosol in company with a fraction of actin and cofilin. At the same time the cells rounded up.

The MADS-box transcription factor SrfA is required for actin cytoskeleton organization and spore coat stability during Dictyostelium sporulation.

The MADS-box transcription factor SrfA is involved in spore differentiation in Dictyostelium [Development 125 (1998) 3801]. Mutant spores show an altered morphology and loss of viability. A detailed structural analysis of mutant spores has been performed to gain insight into the specific aspects of spore differentiation in which SrfA is involved.

Hypertonic signal promotes stability of Dictyostelium spores via a PKA-independent pathway.

Differentiation of Dictyostelium spores initiates with rapid encapsulation of prespore cells under the control of cAMP-dependent protein kinase (PKA), followed by further maturation processes involving cytoskeletal reorganization. Constitutive activation of PKA induces precocious formation of viable spores in development and confers the ability to encapsulate under specific submerged conditions. In this study, we show that the stability of these spores depends upon conditions of high osmotic strength during spore differentiation, indicating that a hypertonic signal is required in addition to PKA to induce maturation to stable spores.

DNA base alignment and taxonomic study of genus Malassezia based upon partial sequences of mitochondrial large subunit ribosomal RNA gene.

The sequences of the large subunit of mitochondrial ribosomal RNA (LsmtrRNA) gene of Malassezia species were analysed. The sequences of the seven species of Malassezia are well separated in each species. Therefore the LsmtrRNA gene is thought to be one of the gene targets for species identification in the genus Malassezia.

Programmed cell death of Pinus nucellus in response to pollen tube penetration.

In ovules of Pinus densiflora, pollen tubes elongate and branch into the nucellar tissue in the direction of the female gametophyte. After pollination, nucellar cells located around the pollen grain and tube die off. We showed here that the nuclei of the nucellar cells were stained by TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick end labeling).

Distribution and movement of Caenorhabditis elegans on a thermal gradient.

To analyze thermal responses of Caenorhabditis elegans in detail, distribution of a worm population and movement of individual worms were examined on a linear, reproducible and broad temperature gradient. Assay methods were improved compared with those reported previously to ensure good motility and dispersion of worms. Well-fed, wild-type worms distributed over a wide temperature range of up to 10 degrees C, and, within this range, worms migrated in both directions of the gradient at similar frequencies without any specific response to the growth temperature in most cases.

[Overview of lipophilic yeast Malassezia: the current status of the molecular diagnosis].

The lipophilic yeast, genus Malassezia is a part of the normal cutaneous microflora of human and warm-blooded vertebrates. Species of the genera were re-classified to seven species; M. pachydermatis, M.

Comparison of different methods for extraction of mitochondrial DNA from human pathogenic yeasts.

Methods of rapidly extracting chromosomal DNA from human pathogenic yeasts were used in mitochondrial DNA (mtDNA) studies. This paper is concerned with rapid and reliable methods of extracting mtDNA for sequence analysis for species or strain identification, and epidemiological study of medically important fungi and fungal infections. To determine the optimal method of mtDNA extraction without isolating mitochondria, we examined three commonly used methods: 1).