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1.
H. Kobayashi  A. Yamada 《Mycoscience》2003,44(1):0061-0062
 Chlamydospores of Entoloma clypeatum f. hybridum were described on the mycorrhizas and rhizomorphs associated with Rosa multiflora. Their developmental pattern seems to be the Nyctalis type. This is the first report on chlamydospore formation on the mycorrhizae in entolomatoid fungi. Received: January 17, 2002 / Accepted: November 5, 2002 Acknowledgments K.H. is grateful to Emeritus Professor N. Sagara in Kyoto University, in whose laboratory part of this study was undertaken. Thanks are due to Mr. D. Sakuma for allowing the specimens to be kept in Osaka Museum of Natural History. Correspondence to:H. Kobayashi  相似文献   

2.
Ophiodothella caseariae sp. nov. from leaves of Casearia tremula in Venezuela is described and illustrated. Received: February 19, 2002 / Accepted: April 30, 2002  相似文献   

3.
Summary. Arabino-Galactan Proteins (AGPs) were isolated from Chios mastic gum (CMG) by using a buffer containing 0.1 M NaCl, 20 mM Tris–HCl, pH 7.5. Protein analytical methods, combined with specific procedures for carbohydrate characterization, indicated the presence of highly glycosylated protein backbone. In particular, staining by Yariv reagent of the electrophoretically separated molecules revealed the existence of arabinose and galactose and such a modification is characteristic for AGPs. After experiments involving extensive dialysis of the isolated extracts against water and atomic absorption, there was evidence of the existence of zinc ions that are probably covalently bound to the AGPs. By using anion-exchange chromatography, capillary electrophoresis, colorimetric methods and GC-MS, it was found that the extracts were separated into three major populations (A, B, and C), which were consistent with their respective negative charge content namely, uronic acid. The characterization of neutral sugars that was investigated with GC-MS showed the existence of arabinose and galactose in different amounts for each group. Experiments concerning the inhibition of growth of Helicobacter pylori in the presence of AGPs, as is shown for other CMG constituents, showed that the extracts of at least 1.4 g CMG affected the viability of the bacterium. There is no evidence as to whether the AGPs provoke abnormal morphologies of H. pylori, as is reported for the total CMG, or for O-glycans that possess terminal α1, 4-linked N-acetylglucosamine and are expressed in the human gastric mucosa; this has to be further investigated. Authors’ address: Theodora Choli-Papadopoulou, Laboratory of Biochemistry, School of Chemistry, Aristotle University of Thessaloniki, TK 54124 Thessaloniki, Greece  相似文献   

4.
5.
 A new species of Erysiphe sect. Uncinula is described and illustrated from Patagonia, Argentina. Erysiphe patagoniaca sp. nov., found on leaves of Nothofagus × antarctica, is similar to E. nothofagi and E. kenjiana, but differs in its appendages being twisted throughout their length and the number of appendages, asci, and ascospores. The two endemic species of Erysiphe sect. Uncinula, E. magellanica and E. nothofagi, coexisted on the same leaves together with Erysiphe patagoniaca. Received: September 19, 2002 / Accepted: November 28, 2002 Acknowledgments The authors are grateful to Ms. Seiko Niinomi for providing the micrographs of ascomata of Erysiphe spp. on Nothofagus. Correspondence to:S. Takamatsu  相似文献   

6.
B incompatibility factor mutants (Bmut) in Pleurotus ostreatus were recovered from common-B mating heterokaryons resulted from matings between wild-type monokaryons with different A but the same B factors (A1B2 and A2B2) after NTG mutagenesis. The mutant monokaryons such as A1B2mut and A2B2mut were observed to have regularly uninucleated hyphal cells and to be compatible with each other. Matings between A1B2mut and A2B2mut monokaryons produced stable heterokaryons (A1B2mut + A2B2mut) that had binucleated hyphal cells with true clamp connections and formed normal fruit-bodies. Mating tests using basidiospore progeny from each of these heterokaryons revealed the bipolar mating pattern. Genetic analysis suggested that the mutation of B factor in P. ostreatus might occur in the B incompatibility factor genes. Received: August 3, 2001 / Accepted: January 18, 2002  相似文献   

7.
 Two Exobasidium species causing Exobasidium leaf blister on Rhododendron spp. are described. An Exobasidium leaf blister on Rhododendron yedoense var. yedoense f. yedoense has been recognized in Hokkaido Prefecture, Japan, since the first report was issued in 1950. The causal fungus is identified with Exobasidium dubium from the morphology of its hymenial structure and mode of germination of the basidiospores. Another Exobasidium leaf blister on Rhododendron dauricum has been observed in Hokkaido Prefecture, Japan. In comparison with morphology based on hymenial structure and mode of germination of the basidiospores of the 100 validly described taxa, this fungus differs from those known taxa in the size of basidia and basidiospores, the numbers of sterigmata and septa of basidiospores, and the mode of germination of basidiospores. Thus, a new species, Exobasidium miyabei, is established and illustrated. Received: February 13, 2002 / Accepted: September 25, 2002  Present address: National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan Acknowledgments We profoundly appreciate the cooperation of Dr. V. Melnik in providing Russian papers and Dr. L. Vasilyeva for translating them into English. We thank Prof. H. Takahashi for loaning the materials in the Herbarium of the Hokkaido University Museum and Dr. W. Abe, Graduate School of Science, University of Hokkaido, for his kind help with the sampling of R. dauricum in Teshikaga, Hokkaido Prefecture. This study was supported in part by a Grant-in-Aid for Scientific Research (B) (No. 13460019), Japan Society for the Promotion of Science (JSPS). Contribution No. 171, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba. Correspondence to:M. Kakishima  相似文献   

8.
Our aim was to investigate the capability of each of three genes, 16S rRNA, gyrB and aroE, to discriminate, first, among Bacillus thuringiensis H serotypes; second, among B. thuringiensis serovars from the same H serotype; and third, among B. thuringiensis strains from the same serovar. The 16S rRNA, gyrB and aroE genes were amplified from 21 B. thuringiensis H serotypes and their nucleotide sequences determined. Additional strains from four B. cereus sensu lato species were included for comparison purposes. These sequences were pair-wise compared and phylogenetic relationships were revealed. Each of the three genes under study could discriminate among B. thuringiensis H serotypes. The gyrB and aroE genes showed a discriminatory power among B. thuringiensis H serotypes up to nine fold greater than that of the 16S rRNA gene. The gyrB gene was retained for subsequent analyses to discriminate B. thuringiensis serovars from the same H serotype and to discriminate strains from same serovar. A total of 42 B. thuringiensis strains, which encompassed 25 serovars from 12 H serotypes, were analyzed. The gyrB gene nucleotide sequences were different enough as to be sufficient to discriminate among B. thuringiensis serovars from the same H serotype and among B. thuringiensis strains from the same serovar. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

9.
The effects of phosphorus supply on the outcome of interactions between the hemiparasitic angiosperm Rhinanthus minor L. with its host species Lolium perenne L. were investigated in a glasshouse experiment. Host plants were grown in 3-l pots in the presence and absence of R. minor at limiting (0.13 mm P) and optimal (0.65 mm P) concentrations of phosphorus for the growth of the host species. Phosphorus was supplied at 2-day intervals in the form of half-strength Long Ashton nitrate-based solution with phosphorus concentrations adjusted accordingly. Parasitism by R. minor significantly suppressed host growth, with final biomass losses ranging between 32% and 44%. Phosphorus supply had a marked impact on the outcome of the host-parasite interaction. By the end of the growing period, parasite biomass at 0.65 mm P was 90% lower than that achieved at 0.13 mm P. In contrast, host biomass at 0.65 mm P was 74% higher than achieved at 0.13 mm P, indicting that the negative impact of parasitism on the host species was reduced when phosphorus supply was increased. The effects of phosphorus on the host-parasite association appeared to be mediated by changes in both the morphological characteristics of the host roots and the relative sink strengths of the host and parasite. Received: 29 May 1999 / Accepted: 20 December 1999  相似文献   

10.
To identify a molecular marker closely linked to Vrn-B1, the Vrn-1 ortholog on chromosome 5B, sequence polymorphism at four orthologous RFLP loci closely linked to the Vrn-1 gene family was analyzed by using near-isogenic lines of ”Triple Dirk.” At Xwg644, a RFLP locus, three types of nucleotide sequence differing by the number of (TG) repeats, two or three times, and base changes were detected. A (TG)3-type sequence proved to be specific to chromosome 5B by nulli-tetrasomic analysis, and substitution of single nucleotide (C/T) was detected between TD(B) carrying the former Vrn2 allele and TD(C) carrying the vrn2 allele. A mismatch primer was designed for dCAPS analysis of this single nucleotide polymorphism (SNP). Polymorphism was successfully detected between two NILs, through nested PCR by using a (TG)3-specific primer (1st) and a dCAPS primer (2nd) followed by a NsiI digest. The analysis of a BF2 population [(TD(B)//TD(C)] revealed the close linkage (1.7 cM) between WG644–5B and Vrn2. It was therefore concluded that the former Vrn2 locus is located on chromosome 5B and equivalent to Vrn-B1. Received: 3 May 2001 / Accepted: 19 July 2001  相似文献   

11.
12.
Two uvrA-like genes, designated uvrA1 and uvrA2, that may be involved in nucleotide excision repair in Xanthomonas axonopodis pv. citri (X. a. pv. citri) strain XW47 were characterized. The uvrA1 gene was found to be 2,964 bp in length capable of encoding a protein of 987 amino acids. The uvrA2 gene was determined to be 2,529 bp with a coding potential of 842 amino acids. These two proteins share 71 and 39% identity, respectively, in amino acid sequence with the UvrA protein of Escherichia coli. Analyses of the deduced amino acid sequence revealed that UvrA1 and UvrA2 have structures characteristic of UvrA proteins, including the Walker A and Walker B motifs, zinc finger DNA binding domains, and helix-turn-helix motif with a polyglycine hinge region. The uvrA1 or uvrA2 mutant, constructed by gene replacement, was more sensitive to DNA-damaging agents methylmethane sulfonate (MMS), mitomycin C (MMC), or ultraviolet (UV) than the wild type. The uvrA1 mutant was four orders of magnitude more sensitive to UV irradiation and two orders of magnitude more sensitive to MMS than the uvrA2 mutant. The uvrA1uvrA2 double mutant was one order of magnitude more sensitive to MMS, MMC, or UV than the uvrA1 single mutant. These results suggest that UvrA1 plays a more important role than UvrA2 in DNA repair in X. a. pv. citri. Both uvrA1 and uvrA2 genes were found to be constitutively expressed in the wild type and lexA1 or lexA2 mutant of X. a. pv. citri, and treatment of these cells with sublethal dose of MMC did not alter the expression of these two genes. Results of electrophoresis mobility shift assays revealed that LexA1 or LexA2 does not bind to either the uvrA1 or the uvrA2 promoter. These results suggest that uvrA expression in X. a. pv. citri is not regulated by the SOS response system.  相似文献   

13.
A comparative study of Lachancea kluyveri strains isolated in Europe, North America, Japan, and the Russian Far East was performed using restriction analysis, sequencing of non-coding rDNA regions, molecular karyotyping, and the phylogenetic analysis of the α-galactosidase MEL genes. This study showed a close genetic relatedness of these L. kluyveri strains. The chromosomal DNAs of the L. kluyveri strains were found to range in size from 980 to 3100 kb. The haploid number of chromosomes is equal to eight. The IGS2 restriction patterns and single nucleotide substitutions in the ITS1/ITS2 rDNA region correlate neither with geographic origin nor with the source of the strains. The L. kluyveri strains isolated from different sources have a high degree of homology (79–100%) of their MEL genes. The phylogenetic analysis of all of the known α-galactosidases in the “Saccharomyces” clade showed that the MEL genes of the yeasts L. kluyveri, L. cidri, Saccharomyces cerevisiae, S. paradoxus, S. bayanus, and S. mikatae are species specific.  相似文献   

14.
Umbelopsis gibberispora is described as a new species in the genus Umbelopsis, Umbelopsidaceae, Mucorales. The species differs from others in this genus by ellipsoidal sporangiospores with unilaterally thickened walls. Phylogenetic analyses based on nuclear large subunit ribosomal DNA (nLSU rDNA) partial sequences suggest that U. gibberispora, U. swartii, and U. westeae form a clade together with the strains of Umbelopsis ramanniana. The ex-type strain of Micromucor ramannianus var. angulisporus is found to be very close to Umbelopsis vinacea, whereas other isolates identified under the former name in the sense of Linnemann fall in the U. ramanniana subclade. For these isolates, a new species, Umbelopsis angularis, is introduced. Phylogenetic relationships among Umbelopsis species are discussed related to their attributes of the sporangial wall and mature spore shapes. Received: August 27, 2002 / Accepted: March 11, 2003 Acknowledgments We thank Dr. Takashi Ohsono, Graduate School of Agriculture, Kyoto University, Japan, for providing the strain of U. gibberispora (CBS 109328). We also thank Dr. Wieland Meyer, University of Sydney, Australia for access to the phylogenetic tree based on ITS sequence data before publishing, and Dr. Richard C. Summerbell, Centraalbureau von Schimmelcultures, the Netherlands, for linguistic corrections.  相似文献   

15.
Birch J  Ellis SA 《Immunogenetics》2007,59(4):273-280
Natural killer cell responses are controlled to a large extent by the interaction of an array of inhibitory and activating receptors with their ligands. The mostly nonpolymorphic CD94/NKG2 receptors in both humans and mice were shown to recognize a single nonclassical MHC class I molecule in each case. In this paper, we describe the CD94/NKG2 gene family in cattle. NKG2 and CD94 sequences were amplified from cDNA derived from four animals. Four CD94 sequences, ten NKG2A, and three NKG2C sequences were identified in total. In contrast to human, we show that cattle have multiple distinct NKG2A genes, some of which show minor allelic variation. All of the sequences designated NKG2A have two tyrosine-based inhibitory motifs in the cytoplasmic domain and one putative gene has, in addition, a charged residue in the transmembrane domain. NKG2C appears to be essentially monomorphic in cattle. All of the NKG2A sequences are similar apart from NKG2A-01, which, in contrast, shares the majority of its carbohydrate recognition domain with NKG2-C. Most of the genes appear to generate multiple alternatively spliced forms. These findings suggest that the CD94/NKG2A heterodimers in cattle, in contrast to other species, are binding several different ligands. Because NKG2C is not polymorphic, this raises questions as to the combined functional capacity of the CD94/NKG2 gene families in cattle.  相似文献   

16.
17.
Hao da C  Yang L  Huang B 《Genetica》2009,135(2):123-135
Evolutionary patterns of sequence divergence were analyzed in genes from the conifer genus Taxus (yew), encoding paclitaxel biosynthetic enzymes taxadiene synthase (TS) and 10-deacetylbaccatin III-10β-O-acetyltransferase (DBAT). N-terminal fragments of TS, full-length DBAT and internal transcribed spacer (ITS) were amplified from 15 closely related Taxus species and sequenced. Premature stop codons were not found in TS and DBAT sequences. Codon usage bias was not found, suggesting that synonymous mutations are selectively neutral. TS and DBAT gene trees are not consistent with the ITS tree, where species formed monophyletic clades. In fact, for both genes, alleles were sometimes shared across species and parallel amino acid substitutions were identified. While both TS and DBAT are, overall, under purifying selection, we identified a number of amino acids of TS under positive selection based on inference using maximum likelihood models. Positively selected amino acids in the N-terminal region of TS suggest that this region might be more important for enzyme function than previously thought. Moreover, we identify lineages with significantly elevated rates of amino acid substitution using a genetic algorithm. These findings demonstrate that the pattern of adaptive paclitaxel biosynthetic enzyme evolution can be documented between closely related Taxus species, where species-specific taxane metabolism has evolved recently.  相似文献   

18.
T. Hosoya  S. Huhtinen 《Mycoscience》2002,43(5):0405-0409
Hyaloscypha albohyalina var. monodictys, a new variety in the family Hyaloscyphaceae, Helotiales with Monodictys anamorph is described and illustrated. Received: June 26, 2002 / Accepted: July 27, 2002 Present address: Strategic Product Portfolio Department, Sankyo Co., Ltd., 3-5-1 Nihonbashi-Honcho, Chuo-ku, Tokyo 103-8426, Japan Tel. +81-3-5255-7040 (Ext. 2528); Fax +81-3-5255-7086 e-mail: hosoya@hq.sankyo.co.jp Correspondence to:T. Hosoya  相似文献   

19.
H. Takahashi 《Mycoscience》2003,44(2):0103-0107
 Three new species of Agaricales from eastern Honshu, Japan, are described and illustrated. (1) Clitocybe minutella sp. nov. (section Vernae), having white, very small, clitocyboid basidiomata with white, strigose mycelial tomentum at the base of the stipe and trichodermial elements in the pileipellis, occurs on leaf litter in deciduous oak forests. (2) Crepidotus longicomatus sp.nov. (section Echinospori), forms very small (up to 3.5 mm in diameter), reniform basidiomata densely covered overall with white to pale yellow, erect, thick-walled, long hairs. It has melleous, echinulate basidiospores, and was found on fallen dead branches in lowland oak forests. (3) Crepidotus virgineus sp. nov. (section Crepidotus), forming pure white, reniform basidiomata, has smooth, ellipsoid basidiospores, subfusiform-pedicellate to irregularly cylindrical cheilocystidia, and abundant clamp connections. It occurs on fallen dead branches in lowland oak forests. Received: August 22, 2002 / Accepted: January 8, 2003 Acknowledgments I am grateful to Dr. Yousuke Degawa (KPM) for allowing the specimens cited to be kept in the Kanagawa Prefectural Museum of Natural History. Correspondence to:H. Takahashi  相似文献   

20.
Mycoses due to yeasts belonging to other genera than Candida have become common in the last years especially in immuno-compromised patients. Species of the anamorphic basidiomycetous yeast genus Trichosporon are such opportunistic human pathogenic yeasts which cause several diseases. In this study, Trichosporon faecale is reported in Germany for the first time. The isolate was taken from a human foot, where it was associated with a tinea pedis. The fungal isolate was identified by investigating the morphology, physiology by a commercial API 32 C-set and molecular data of SSU and LSU rDNA as well as the ITS region.  相似文献   

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