Search results for "FUNGAL"

Sequences of isopenicillin N synthetase genes suggest horizontal gene transfer from prokaryotes to eukaryotes

1990

Evolutionary distances between bacterial and fungal isopenicillin N synthetase (IPNS) genes have been compared to distances between the corresponding 5S rRNA genes. The presence of sequences homologous to the IPNS gene has been examined in DNAs from representative prokaryotic organisms and Ascomycotina. The results of both analyses strongly support two different events of horizontal transfer of the IPNS gene from bacteria to filamentous fungi. This is the first example of such a type of transfer from prokaryotes to eukaryotes.

Molecular Characterization of Fusarium oxysporum f. melongenae by ISSR and RAPD Markers on Eggplant

2010

Fusarium oxysporum f. melongenae is a major soil-borne pathogen of eggplant (Solanum melongena). ISSR and RAPD markers were used to characterize Fusarium oxysporum f. melongenae isolates collected from eggplant fields in southern Turkey. Those isolates were not pathogenic to tomato. Pathogens were identified by their morphology, and their identity was confirmed by PCR amplifi- cation using the specific primer PF02-3. The isolates were classified into groups on the basis of ISSR and RAPD fingerprints, which showed a level of genetic speci- ficity and diversity not previously identified in Fusarium oxysporum f. melongenae, suggesting that genetic differences are related to the pathogen in the…

Basic phenotypic analysis of six novel yeast genes reveals two essential genes and one which affects the growth rate

1999

Phenotypic analysis was performed on six mutants of Saccharomyces cerevisiae deleted in one of the following open reading frames (ORFs), located on chromosome II: YBR254c, YBR255w, YBR257w, YBR258c, YBR259w and YBR266c. Disruption of the ORFs was carried out in the diploid strain FY1679 using the kanMX4 marker flanked by short sequences homologous to the target locus. Tetrad analysis following sporulation of the heterozygous disruptants showed that YBR254c and YBR257w are essential genes. YBR257w was later characterized and renamed POP4, its gene product being involved in 5.8S rRNA and tRNA processing (Chu et al., 1997). The tetrad analysis performed for the heterozygous disruptant for YBR2…

Clonal population structure of the chestnut blight fungus in expanding ranges in southeastern Europe.

2008

Expanding populations are often less genetically diverse at their margins than at the centre of a species' range. Established, older populations of the chestnut blight fungus, Cryphonectria parasitica, are more variable for vegetative compatibility (vc) types than in expanding populations in southeastern Europe where C. parasitica has colonized relatively recently. To test whether vc types represent clones, we genotyped 373 isolates of C. parasitica from southern Italy, Romania, Bulgaria, Macedonia, Greece and Turkey using 11 sequence-characterized amplified region (SCAR) markers. Ten SCAR loci and six vegetative incompatibility (vic) loci were polymorphic in these samples. These population…

Molecular Characterization of a Chromosomal Rearrangement Involved in the Adaptive Evolution of Yeast Strains

2002

Wine yeast strains show a high level of chromosome length polymorphism. This polymorphism is mainly generated by illegitimate recombination mediated by Ty transposons or subtelomeric repeated sequences. We have found, however, that the SSU1-R allele, which confers sulfite resistance to yeast cells, is the product of a reciprocal translocation between chromosomes VIII and XVI due to unequal crossing-over mediated by microhomology between very short sequences on the 5' upstream regions of the SSU1 and ECM34 genes. We also show that this translocation is only present in wine yeast strains, suggesting that the use for millennia of sulfite as a preservative in wine production could have favored …

Multiplex PCR for species discrimination of Sclerotiniaceae by novel laccase introns

2006

Common PCR-based targets for the identification of filamentous fungi and yeasts are the sequences of the internal transcribed spacer region (ITS1, 5.8S rDNA, ITS2). Within the Sclerotiniaceae the ITS-region is homogenous and the identification is almost impossible. Furthermore, the lack of IGS-data (intergenic spacer region) requires new specific marker genes for a rapid identification of phytopathogenic Sclerotiniaceae. We sequenced and analyzed new laccase2 (lcc2) genes from the phylogenetically related Sclerotinia sclerotiorum (Lib.) de Bary, Sclerotinia minor Jagger, and Monilinia fructigena Honey. Comparative analysis revealed remarkable differences in length and sequence compared to t…

Chromatin structure of yeast genes.

1989

BRG1 and NRG1 form a novel feedback circuit regulating Candida albicans hypha formation and virulence

2012

In the opportunistic fungal pathogen Candida albicans both cellular morphology and the capacity to cause disease are regulated by the transcriptional repressor Nrg1p. One of the genes repressed by Nrg1p is BRG1, which encodes a putative GATA family transcription factor. Deletion of both copies of this gene prevents hypha formation. We discovered that BRG1 over-expression is sufficient to overcome Nrg1p-mediated repression and drive the morphogenetic shift from yeast to hyphae even in the absence of environmental stimuli. We further observed that expression of BRG1 influences the stability of the NRG1 transcript, thus controlling filamentation through a feedback loop. Analysis of this phenom…

Differential expression of SUC genes: A question of bases

1994

Non-coding nucleotide sequences located 5' upstream of the transcriptional start site play an essential role in gene expression as they contain binding sites for transcription and regulatory factors. The yeast SUC gene family is a useful model to study the influence that nucleotide exchanges within the promoter regions have on their expression, since (i) these genes, regulated by glucose repression, are differentially transcribed (invertase activity produced by distinct SUC genes may show variations of about 10-fold); and (ii) promoter sequences of SUC3, SUC4, SUC5 and SUC7 are more than 99% homologous, showing only six base exchanges among all of them. Comparison of these nucleotide exchan…

Self-diploidization in Saccharomyces cerevisiae kar2 heterokaryons

1993

Zygotes isolated by micromanipulation from crosses of Saccharomyces cerevisiae strains, one of which carries a kar mutation, give rise most frequently to cytoductant colonies showing the nuclear constitution of either one of the two haploid parental strains. In crosses of kar2-1 strains to wild-type, about 10% of the cytoductants of both mating types are homozygous autodiploids. There is evidence indicating that self-diploidization occurs by fusion between sibling nuclei in the heterokaryotic zygote. Here we describe this phenomenon and propose to take advantage of it for the construction of genotypically-defined diploids able to mate, and of polyploid strains, which are useful tools in gen…