Mycoscience
Online ISSN : 1618-2545
Print ISSN : 1340-3540
Volume 52, Issue 2
Displaying 1-11 of 11 articles from this issue
Review
  • Masatoshi Saikawa
    2011 Volume 52 Issue 2 Pages 83-90
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    The morphology of fungi in the Zoopagaceae and Cochlonemataceae (Zoopagales, Zoopagomycotina, Zygomycota) is reviewed, and some new ultrastructural information is added on conidia and zygospores, as well as haustoria in the former family and vegetative thalli in the latter. The cell wall of the conidia of Acaulopage dichotoma, Ac. tetraceros, Stylopage cephalote, Zoophagus insidians, and Zph. tentaclum (Zoopagaceae), and of Cochlonema odontosperma and Endocochlus gigas (Cochlonemataceae), is known to be composed of outer electron-dense and inner less dense layers in ultrathin sections, and no additional cell walls were found on the conidial cell wall. Although two nuclei were found in the zygosporangium before maturation to the zygospore in Acaulopage rhaphidospora (Zoopagaceae), more than one nucleus had never been observed previously in a zygospore in either of these families in ultrathin sections.

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Full Paper
  • Yoshio Ogawa, Masato Sugiyama, Dai Hirose, Kuniko Kusama-Eguchi, Seiji ...
    2011 Volume 52 Issue 2 Pages 91-98
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    The taxonomic positions of three intraspecific groups of Umbelopsis ramanniana in the genus Umbelopsis were analyzed based on the nucleotide sequences of their nuclear large subunit ribosomal DNA (nLSU rDNA) D1/D2 region. The examined members of the genus Umbelopsis were resolved into two major clades, Clades I and II. The intraspecific groups of U. ramanniana were nested within Clade II together with U. westeae, U. swartii, U. autotrophica, U. gibberisopra, U. angularis, and U. fusiformis. In this major clade, the intraspecific groups of U. ramanniana were split into three polyphyletic subclades. This suggests that U. ramanniana is an assemblage of several genetically distinct species. Interestingly, in spite of the diverse sporangiospore shapes of the members of Clade II, the genetic variation among them was small. It is considered that their flexible sporangia membranes make it possible for them to develop various sporangiospore shapes.

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  • Hiroyoshi Kubo
    2011 Volume 52 Issue 2 Pages 99-106
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Putative glyceraldehyde-3-phosphate dehydrogenase (gapdh) genes were cloned from Pilobolus crystallinus with degenerated primers designed from conserved sequences in many GAPDHs. P. crystallinus had three gapdh homologue genes, named pcgapdh1, pcgapdh2, and pcgapdh3. Deduced amino acid sequences for PCGAPDH1, PCGAPDH2, and PCGAPDH3 showed highest similarity with GPD3, GPD1, and GPD2, respectively, of Mucor circinelloides, indicating that these three gapdh genes had diverged before Pilobolus and Mucor were separated. The expression patterns of the gapdh genes, however, were quite different between P. crystallinus and M. circinelloides. All the three pcgapdh genes were expressed, and the expression of pcgapdh2 was suppressed by glucose and sodium acetate. These results indicate that the function of these orthologous genes was changed after Pilobolus and Mucor were separated.

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  • Sarath N. Arseculeratne, Navaratne B. Eriyagama
    2011 Volume 52 Issue 2 Pages 107-110
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Rhinosporidiosis in humans and animals, caused by Rhinosporidium seeberi, can now be termed an emerging infective disease worldwide. The pharmacokinetics of dapsone when used as an antimicrobial agent in patients with rhinosporidiosis was compared with its pharmacodynamics in the inactivation of purified rhinosporidial endospores in vitro. A marked discrepancy was noted between the in vitro inactivation, which commenced on day 1 and was a maximum at day 4, whereas earlier reports on the response of endospores in patients under dapsone therapy indicated that the degeneration and disappearance of the endospores was not observed for 18–36 weeks after therapy began. Reasons for this discrepancy that operate in vivo are postulated: (a) impermeability of the barriers of down-growths of squamous epithelium in which the endospore-containing rhinosporidial sporangia are embedded; (b) presence of a mucoid matrix in which the endospores exist within the sporangia. These explanations contribute to resolving the controversial problem of general correlations between in vitro and in vivo results from studies on the action of antimicrobial drugs.

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  • Joha W. Grobbelaar, Paulette Bloomer, Michael J. Wingfield, Brenda D. ...
    2011 Volume 52 Issue 2 Pages 111-118
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Ophiostoma species such as O. quercus are the most frequent causal agents of sapstain of freshly felled hardwood timber and pulpwood. Many species are regarded as economically important agents of wood degradation. The aim of this study was to identify a collection of Ophiostoma isolates, resembling O. quercus, found on stained Eucalyptus pulpwood chips in China. DNA sequences of the internal transcribed spacer regions, including the 5.8 S region, of the ribosomal DNA, and parts of the β-tubulin and elongation factor-1α genes, revealed that the isolates were not O. quercus. Surprisingly, they represented O. tsotsi, a wound-infesting fungus recently described from hardwoods in Africa. In addition, sequence data from an isolate from agarwood in Vietnam, identified in a previous study as belonging to an unknown Pesotum species, were also shown to represent O. tsotsi. A high level of genetic variability was observed among isolates of both O. quercus and O. tsotsi. This was unexpected and suggests that both species have been present in Asia for a significant amount of time.

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  • Daisuke Takuma, Shinpei Wada, Osamu Kurata, Kishio Hatai, Ayako Sano
    2011 Volume 52 Issue 2 Pages 119-131
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    A species of Aphanomyces was isolated from juvenile soft-shelled turtles, Pelodiscus sinensis, cultured in Japan. Typically, an infected turtle showed small whitish maculae on the carapace. Many hyphae were observed in the epidermis. The hyphae were isolated using glucose– yeast (GY) agar plates. The morphological characteristics were very similar to those of Aphanomyces laevis, but a clear nuclear spot was observed in the center of the oospore in the strains isolated from the soft-shelled turtles. The optimal growth temperature for the isolates was 25–30°C and the optimum pH was 6–9. Experimental infection tests with isolates produced small whitish maculae on the carapace, and soft-shelled turtles artificially infected with the zoospores showed high mortality, especially in the highdose group. Phylogenetic analysis based on the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) indicated that the isolates from the soft-shelled turtles were unidentified species of Aphanomyces. As a result, the strain was described as a new species, Aphanomyces sinensis.

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Note
  • Tsuneo Watanabe, Masahiro Tagawa, Hideyuki Tamaki, Satoshi Hanada
    2011 Volume 52 Issue 2 Pages 152-156
    Published: 2011
    Released on J-STAGE: March 31, 2023
    JOURNAL OPEN ACCESS

    Sclerotia were formed in agar culture by a fungus with clamp connections isolated from rice husks at Tsukuba, Japan. The sclerotia were brown, globose to ellipsoidal, small, up to 200 μm in diameter, and composed of external rind tissue and internal medulla tissue. Such tiny sclerotia have not been commonly reported among basidiomycetous fungi in the literature. The fungus was identified as Coprinopsis cinerea on the basis of morphological characteristics together with molecular analyses. Three reference strains of C. cinerea formed sclerotia similarly under identical cultural conditions.

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