The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Lynne Sigler - One of the best experts on this subject based on the ideXlab platform.
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molecular genetic variation in emmonsia crescens and emmonsia parva etiologic agents of adiaspiromycosis and their phylogenetic relationship to blastomyces Dermatitidis Ajellomyces Dermatitidis and other systemic fungal pathogens
Journal of Clinical Microbiology, 1998Co-Authors: Stephen W Peterson, Lynne SiglerAbstract:Emmonsia crescens, an agent of adiaspiromycosis, Blastomyces Dermatitidis, the agent of blastomycosis, and Histoplasma capsulatum, the agent of histoplasmosis, are known to form meiotic (sexual) stages in the ascomycete genus Ajellomyces (Onygenaceae, Onygenales), but no sexual stage is known for E. parva, the type species of the genus Emmonsia. To evaluate relationships among members of the putative Ajellomyces clade, large-subunit ribosomal and internal transcribed spacer region DNA sequences were determined from PCR-amplified DNA fragments. Sequences were analyzed phylogenetically to evaluate the genetic variation within the genus Emmonsia and evolutionary relationships to other taxa. E. crescens and E. parva are distinct species. E. crescens isolates are placed into two groups that correlate with their continents of origin. Considerable variation occurred among isolates previously classified as E. parva. Most isolates are placed into two closely related groups, but the remaining isolates, including some from human sources, are phylogenetically distinct and represent undescribed species. Strains of B. Dermatitidis are a sister species of E. parva. Paracoccidioides brasiliensis and Histoplasma capsulatum are ancestral to most Emmonsia isolates, and P. brasiliensis, which has no known teleomorph, falls within the Ajellomyces clade.
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Ajellomyces crescens sp nov taxonomy of emmonsia spp and relatedness with blastomyces Dermatitidis teleomorph Ajellomyces Dermatitidis
Medical Mycology, 1996Co-Authors: Lynne SiglerAbstract:Adiaspiromycosis is known primarily as a pulmonary infection of small burrowing mammals and rarely of humans, in which the tissue spore form consists of a large, globose, thick-walled, non-proliferating structure called an adiaspore. The causative agents have been placed in Emmonsia or Chrysosporium and treated as either two species or varieties. Emmonsia parva (= Chrysosporium parvum var. parvum) has been distinguished from E. crescens (= C. parvum var. crescens) by differences in maximum growth temperature, size of adiaspores, host range and geographical distribution. Phenotypic similarities between Emmonsia spp. and Blastomyces Dermatitidis and chance observation of Ajellomyces-type ascomatal hyphae led to the hypothesis that the teleomorph of Emmonsia spp. could occur in Ajellomyces. Isolates preliminarily identified as E. parva or E. crescens were examined by morphology and physiology and tested for compatibility in mating experiments. Ajellomyces crescens Sigler sp. nov. is described for the teleomo...
Stephen W Peterson - One of the best experts on this subject based on the ideXlab platform.
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molecular genetic variation in emmonsia crescens and emmonsia parva etiologic agents of adiaspiromycosis and their phylogenetic relationship to blastomyces Dermatitidis Ajellomyces Dermatitidis and other systemic fungal pathogens
Journal of Clinical Microbiology, 1998Co-Authors: Stephen W Peterson, Lynne SiglerAbstract:Emmonsia crescens, an agent of adiaspiromycosis, Blastomyces Dermatitidis, the agent of blastomycosis, and Histoplasma capsulatum, the agent of histoplasmosis, are known to form meiotic (sexual) stages in the ascomycete genus Ajellomyces (Onygenaceae, Onygenales), but no sexual stage is known for E. parva, the type species of the genus Emmonsia. To evaluate relationships among members of the putative Ajellomyces clade, large-subunit ribosomal and internal transcribed spacer region DNA sequences were determined from PCR-amplified DNA fragments. Sequences were analyzed phylogenetically to evaluate the genetic variation within the genus Emmonsia and evolutionary relationships to other taxa. E. crescens and E. parva are distinct species. E. crescens isolates are placed into two groups that correlate with their continents of origin. Considerable variation occurred among isolates previously classified as E. parva. Most isolates are placed into two closely related groups, but the remaining isolates, including some from human sources, are phylogenetically distinct and represent undescribed species. Strains of B. Dermatitidis are a sister species of E. parva. Paracoccidioides brasiliensis and Histoplasma capsulatum are ancestral to most Emmonsia isolates, and P. brasiliensis, which has no known teleomorph, falls within the Ajellomyces clade.
Alex Andrianopoulos - One of the best experts on this subject based on the ideXlab platform.
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Fungal dimorphism: the switch from hyphae to yeast is a specialized morphogenetic adaptation allowing colonization of a host
Fems Microbiology Reviews, 2015Co-Authors: Kylie J. Boyce, Alex AndrianopoulosAbstract:The ability of pathogenic fungi to switch between a multicellular hyphal and unicellular yeast growth form is a tightly regulated process known as dimorphic switching. Dimorphic switching requires the fungus to sense and respond to the host environment and is essential for pathogenicity. This review will focus on the role of dimorphism in fungi commonly called thermally dimorphic fungi, which switch to a yeast growth form during infection. This group of phylogenetically diverse ascomycetes includes Talaromyces marneffei (recently renamed from Penicillium marneffei) , Blastomyces Dermatitidis (teleomorph Ajellomyces Dermatitidis), Coccidioides species (C. immitis and C. posadasii ) , Histoplasma capsulatum (teleomorph Ajellomyces capsulatum), Paracoccidioides species ( P. brasiliensis and P. lutzii ) and Sporothrix schenckii (teleomorph Ophiostoma schenckii ). This review will explore both the signalling pathways regulating the morphological transition and the transcriptional responses necessary for intracellular growth. The physiological requirements of yeast cells during infection will also be discussed, highlighting recent advances in the understanding of the role of iron and calcium acquisition during infection.
Joseph Heitman - One of the best experts on this subject based on the ideXlab platform.
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Identification of the Mating-Type (MAT) Locus That Controls Sexual Reproduction of Blastomyces Dermatitidis
Eukaryotic Cell, 2012Co-Authors: Thomas D. O'sullivan, Anna Floyd Averette, Sharadha Sakthikumar, Bruce S. Klein, Christina A Cuomo, Eric M Walton, Joseph HeitmanAbstract:Blastomyces Dermatitidis is a dimorphic fungal pathogen that primarily causes blastomycosis in the midwestern and northern United States and Canada. While the genes controlling sexual development have been known for a long time, the genes controlling sexual reproduction of B. Dermatitidis (teleomorph, Ajellomyces Dermatitidis) are unknown. We identified the mating-type (MAT) locus in the B. Dermatitidis genome by comparative genomic approaches. The B. Dermatitidis MAT locus resembles those of other dimorphic fungi, containing either an alpha-box (MAT1-1) or an HMG domain (MAT1-2) gene linked to the APN2, SLA2, and COX13 genes. However, in some strains of B. Dermatitidis, the MAT locus harbors transposable elements (TEs) that make it unusually large compared to the MAT locus of other dimorphic fungi. Based on the MAT locus sequences of B. Dermatitidis, we designed specific primers for PCR determination of the mating type. Two B. Dermatitidis isolates of opposite mating types were cocultured on mating medium. Immature sexual structures were observed starting at 3 weeks of coculture, with coiled-hyphae-containing cleistothecia developing over the next 3 to 6 weeks. Genetic recombination was detected in potential progeny by mating-type determination, PCR-restriction fragment length polymorphism (PCR-RFLP), and random amplification of polymorphic DNA (RAPD) analyses, suggesting that a meiotic sexual cycle might have been completed. The F1 progeny were sexually fertile when tested with strains of the opposite mating type. Our studies provide a model for the evolution of the MAT locus in the dimorphic and closely related fungi and open the door to classic genetic analysis and studies on the possible roles of mating and mating type in infection and virulence.
Kylie J. Boyce - One of the best experts on this subject based on the ideXlab platform.
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Fungal dimorphism: the switch from hyphae to yeast is a specialized morphogenetic adaptation allowing colonization of a host
Fems Microbiology Reviews, 2015Co-Authors: Kylie J. Boyce, Alex AndrianopoulosAbstract:The ability of pathogenic fungi to switch between a multicellular hyphal and unicellular yeast growth form is a tightly regulated process known as dimorphic switching. Dimorphic switching requires the fungus to sense and respond to the host environment and is essential for pathogenicity. This review will focus on the role of dimorphism in fungi commonly called thermally dimorphic fungi, which switch to a yeast growth form during infection. This group of phylogenetically diverse ascomycetes includes Talaromyces marneffei (recently renamed from Penicillium marneffei) , Blastomyces Dermatitidis (teleomorph Ajellomyces Dermatitidis), Coccidioides species (C. immitis and C. posadasii ) , Histoplasma capsulatum (teleomorph Ajellomyces capsulatum), Paracoccidioides species ( P. brasiliensis and P. lutzii ) and Sporothrix schenckii (teleomorph Ophiostoma schenckii ). This review will explore both the signalling pathways regulating the morphological transition and the transcriptional responses necessary for intracellular growth. The physiological requirements of yeast cells during infection will also be discussed, highlighting recent advances in the understanding of the role of iron and calcium acquisition during infection.