MEREDITH BLACKWELL - Academia.edu (original) (raw)

Papers by MEREDITH BLACKWELL

Research paper thumbnail of The dispersal of microbes among and within flowers by butterflies

Ecological Entomology, Mar 28, 2023

Research paper thumbnail of Yeasts in Insects and Other Invertebrates

Yeasts in Natural Ecosystems: Diversity, 2017

Minute organisms, including yeasts with diverse physiological capabilities, make possible the exi... more Minute organisms, including yeasts with diverse physiological capabilities, make possible the existence of arthropods, especially insects, the most speciose group of organisms on Earth. The yeast growth form occurs throughout most of the fungal kingdom and is often associated with insects. Fungi and insects evolved together in the same habitats where casual associations certainly occurred early in their shared geological history and yeast attractants for insects developed over their lives together. Examples of their interactions range from accidental dispersal and the use of yeasts as food to obligate mutualisms described in this chapter. These include discussions of yeast-like symbionts, the use of the wasp gut for yeast outcrossing, extension of endophyte life cycles to include dispersal by insects, the advantage of yeasts in the diet of many insects such as blood-sucking dipterans, and the yeast-like germination of phoretic fungi in ephemeral habitats. Future studies of yeast–insect associations will continue to include species discovery but also approach theoretical questions of sexual and asexual reproduction, host specificity, host switching, advantages of horizontal and vertical dispersal, and studies that include entire interactive communities.

Research paper thumbnail of Lives within lives: Hidden fungal biodiversity and the importance of conservation

Research paper thumbnail of Made for Each Other: Ascomycete Yeasts and Insects

Microbiology spectrum, 2017

Fungi and insects live together in the same habitats, and many species of both groups rely on eac... more Fungi and insects live together in the same habitats, and many species of both groups rely on each other for success. Insects, the most successful animals on Earth, cannot produce sterols, essential vitamins, and many enzymes; fungi, often yeast-like in growth form, make up for these deficits. Fungi, however, require constantly replenished substrates because they consume the previous ones, and insects, sometimes lured by volatile fungal compounds, carry fungi directly to a similar, but fresh, habitat. Yeasts associated with insects include Ascomycota (Saccharomycotina, Pezizomycotina) and a few Basidiomycota. Beetles, homopterans, and flies are important associates of fungi, and in turn the insects carry yeasts in pits, specialized external pouches, and modified gut pockets. Some yeasts undergo sexual reproduction within the insect gut, where the genetic diversity of the population is increased, while others, well suited to their stable environment, may never mate. The range of inte...

Research paper thumbnail of The Status and Characterization of Enteroramus dimorphus: A Xylose-Fermenting Yeast Attached to the Gut of Beetles

Research paper thumbnail of Preserving Accuracy in GenBank

Research paper thumbnail of Phylogenetic Distribution of Fungal Sterols

Research paper thumbnail of Five novel Candida species in insect-associated yeast clades isolated from Neuroptera and other insects

Mycologia, 2007

Ascomycete yeasts are found commonly in the guts of basidioma-feeding beetles but little is known... more Ascomycete yeasts are found commonly in the guts of basidioma-feeding beetles but little is known about their occurrence in the gut of other insects. In this study we isolated 95 yeasts from the gut of adult insects in five neuropteran families (Neuroptera: Corydalidae, Chrysopidae, Ascalaphidae, Mantispidae and Hemerobiidae) and a roach (Blattodea: Blattidae). Based on DNA sequence comparisons and other taxonomic characteristics, they were identified as more than 15 species of Saccharomycetes as well as occasional Cryptococcus-like basidiomycete yeasts. Yeast species such as Lachancea fermentati, Lachancea thermotolerans and Hanseniaspora vineae were isolated repeatedly from the gut of three species of corydalids, suggesting a close association of these species and their insect hosts. Among the yeasts isolated in this study 12 were identified as five novel Candida species that occurred in three phylogenetically distinct clades. Molecular phylogenetic analyses showed that Candida chauliodes sp. nov. (NRRL Y-27909T) and Candida corydali sp. nov. (NRRL Y-27910T) were sister taxa in the Candida albicans/ Lodderomyces elongisporus clade. Candida dosseyi sp. nov. (NRRL Y-27950T) and Candida blattae sp. nov. (NRRL Y-27698T) were sister taxa in the Candida intermedia clade. Candida ascalaphidarum sp. nov. (NRRL Y-27908T) fell on a basal branch in a clade containing Candida membranifaciens and many other insect-associated species. Descriptions of these novel yeast species are provided as well as discussion of their ecology in relation to their insect hosts.

Research paper thumbnail of Phylogenetics of Saccharomycetales, the ascomycete yeasts

Research paper thumbnail of Phylogeny of Asexual Fungi Associated with Bark and Ambrosia Beetles

Research paper thumbnail of Distribution and sporulation phenology of myxomycetes in the Sonoran Desert of Arizona

Microbial Ecology, 1984

All pith samples from 68 dead saguaro cacti in 3 plots and 11 isolated dead plants in Saguaro Nat... more All pith samples from 68 dead saguaro cacti in 3 plots and 11 isolated dead plants in Saguaro National Monument, Arizona, produced at least one species of myxomycete upon incubation at 20 or 30°C. Three species,Badhamia gracilis (Macbr.) Macbr.,Physarum straminipes Lister, andDidymium eremophilum M. Blackwell et Gilbertson, developed at high frequencies on the substrates in moist chamber culture.Perichaena corticalis (Batsch) Rost, andProtophysarum phloiogenum M. Blackwell et Alexopoulos were also present. Although previous literature reports [9] indicated that Myxomycetes grow best at low pH, these species all tolerated substrates of pH 8.7-10.4.Didymium eremophilum andP. phloiogenum had peaks in sporulation within 6 days; other species were slower. There was no difference in time of sporulation ofB. gracilis orD. eremophilum at 20 and 30°C; however, sporulation ofP. straminipes was significantly later at 30°C. Reduced spore germination and slower buildup of critically sized amoebal populations ofP. straminipes at 30°C may be a factor.

Research paper thumbnail of A Group I Intron in the Nuclear Small Subunit rRNA Gene of Cryptendoxyla hypophloia, an Ascomycetous Fungus: Evidence for a New Major Class of Group I Introns

Journal of Molecular Evolution, 1999

Research paper thumbnail of Morphological and ecological similarities: wood-boring beetles associated with novel xylose-fermenting yeasts, Spathaspora passalidarum gen. sp. nov. and Candida jeffriesii sp. nov

Mycological Research, 2006

Ascomycete yeasts that both ferment and assimilate xylose were reported previously as associates ... more Ascomycete yeasts that both ferment and assimilate xylose were reported previously as associates of insects living in woody substrates. Most notable have been reports of Pichia stipitis-like yeasts that are widely associated with the wood-boring beetle, Odontotaenius disjunctus (Coleoptera: Passalidae), in the eastern United States. Our continuing investigation of insect gut yeasts has lead to the discovery of two new xylose-fermenting yeasts that phylogenetic analysis places as sister taxa. The beetle hosts, O. disjunctus and Phrenapates bennetti (Coleoptera: Tenebrionidae), are similar in habitat and appearance, and the presence of similar gut yeasts is an additional common feature between them. Here we describe the new yeast genus Spathaspora, the type species S. passalidarum, and its sister taxon Candida jeffriesii and discuss their natural history, including a comparison with Pichia stipitis, another member of a guild of xylose-fermenting yeasts with similar metabolic traits. In addition a morphologically distinct yeast ascospore type is described for Spathaspora.

Research paper thumbnail of Molecular data support the Laboulbeniales as a separate class of Ascomycota, Laboulbeniomycetes

Mycological Research, 2001

The Laboulbeniales have had a clouded taxonomic history. Initially interpreted as abnormal cuticu... more The Laboulbeniales have had a clouded taxonomic history. Initially interpreted as abnormal cuticular outgrowths of arthropods, they have since been considered to be acanthocephalans, basidiomycetes, and zygomycetes as well as ascomycetes. ...

Research paper thumbnail of Ascospores of Pyxidiophora on mites associated with beetles in trees and wood

Mycological Research, 1989

Research paper thumbnail of Metschnikowia noctiluminum sp. nov., Metschnikowia corniflorae sp. nov., and Candida chrysomelidarum sp. nov., isolated from green lacewings and beetles

Mycological Research, 2006

Fourteen yeast isolates belonging to the Metschnikowia clade were isolated from the digestive tra... more Fourteen yeast isolates belonging to the Metschnikowia clade were isolated from the digestive tracts of lacewings (Neuroptera: Chrysopidae), soldier beetles and leaf beetles (Coleoptera: Cantharidae and Chrysomelidae), and a caddisfly (Trichoptera: Hydropsychidae). The insect hosts were associated with sugary substances of plants, a typical habitat for yeasts in this clade. Based on DNA sequence comparisons and phenetic characters, the yeasts were identified as Candida picachoensis, Candida pimensis, and four undescribed taxa. Among the undescribed taxa, three yeasts were distinguished from one another and from other described taxa by nucleotide differences in the ribosomal DNA repeat, which were sufficient to consider them as new species. Two of the novel yeast species are described as Metschnikowia noctiluminum (NRRL Y-27753(T)) and M. cornifloraespp. nov. (NRRL Y-27750(T)) based in part on production of needle-shaped ascospores, which are found in most Metschnikowia species. Sexual reproduction was not observed in the third new yeast, Candida chrysomelidarumsp. nov. (NRRL Y-27749(T)). A fourth isolate, NRRL Y-27752, was not significantly distinct from Metschnikowia viticola and Candida kofuensis to be described as a new species. Phylogenetic analysis of the D1/D2 loop sequences placed M. noctiluminum within the M. viticola clade, while C. chrysomelidarum was a sister taxon of Candida rancensis. Metschnikowia corniflorae was phylogenetically distinct from other new species and fell outside of the large-spored Metschnikowia group.

Research paper thumbnail of The polyphyletic origins of ophiostomatoid fungi

Mycological Research, 1994

... 1-9 (1994) Printed in Great Britain I The polyphyletic origins of ophiostomatoid fungi JOSEPH... more ... 1-9 (1994) Printed in Great Britain I The polyphyletic origins of ophiostomatoid fungi JOSEPH W. SPATAFORA* AND MEREDITH BLACKWELL Department ... 1951; Hunt, 1956; Olchowecki & Reid, 1974; Upadhyay, 1981), in different families of the same order (de Hoog, 1974; von ...

Research paper thumbnail of Marchandiobasidium aurantiacum gen. sp. nov., the teleomorph of Marchandiomyces aurantiacus (Basidiomycota, Ceratobasidiales)

Mycological Research, 2003

Research paper thumbnail of Three new beetle-associated yeast species in the clade

FEMS Yeast Research, 2004

Research paper thumbnail of Fungal evolution and taxonomy

BioControl, 2009

Fungi and insects are closely associated in many terrestrial and some aquatic habitats. In additi... more Fungi and insects are closely associated in many terrestrial and some aquatic habitats. In addition to the pathogenic associations, many more interactions involve fungal spore dispersal. Recent advances in the study of insect-associated fungi have come from phylogenic analyses with increased taxon sampling and additional DNA loci. In addition to providing stable phylogenies, some molecular studies have begun to unravel

Research paper thumbnail of The dispersal of microbes among and within flowers by butterflies

Ecological Entomology, Mar 28, 2023

Research paper thumbnail of Yeasts in Insects and Other Invertebrates

Yeasts in Natural Ecosystems: Diversity, 2017

Minute organisms, including yeasts with diverse physiological capabilities, make possible the exi... more Minute organisms, including yeasts with diverse physiological capabilities, make possible the existence of arthropods, especially insects, the most speciose group of organisms on Earth. The yeast growth form occurs throughout most of the fungal kingdom and is often associated with insects. Fungi and insects evolved together in the same habitats where casual associations certainly occurred early in their shared geological history and yeast attractants for insects developed over their lives together. Examples of their interactions range from accidental dispersal and the use of yeasts as food to obligate mutualisms described in this chapter. These include discussions of yeast-like symbionts, the use of the wasp gut for yeast outcrossing, extension of endophyte life cycles to include dispersal by insects, the advantage of yeasts in the diet of many insects such as blood-sucking dipterans, and the yeast-like germination of phoretic fungi in ephemeral habitats. Future studies of yeast–insect associations will continue to include species discovery but also approach theoretical questions of sexual and asexual reproduction, host specificity, host switching, advantages of horizontal and vertical dispersal, and studies that include entire interactive communities.

Research paper thumbnail of Lives within lives: Hidden fungal biodiversity and the importance of conservation

Research paper thumbnail of Made for Each Other: Ascomycete Yeasts and Insects

Microbiology spectrum, 2017

Fungi and insects live together in the same habitats, and many species of both groups rely on eac... more Fungi and insects live together in the same habitats, and many species of both groups rely on each other for success. Insects, the most successful animals on Earth, cannot produce sterols, essential vitamins, and many enzymes; fungi, often yeast-like in growth form, make up for these deficits. Fungi, however, require constantly replenished substrates because they consume the previous ones, and insects, sometimes lured by volatile fungal compounds, carry fungi directly to a similar, but fresh, habitat. Yeasts associated with insects include Ascomycota (Saccharomycotina, Pezizomycotina) and a few Basidiomycota. Beetles, homopterans, and flies are important associates of fungi, and in turn the insects carry yeasts in pits, specialized external pouches, and modified gut pockets. Some yeasts undergo sexual reproduction within the insect gut, where the genetic diversity of the population is increased, while others, well suited to their stable environment, may never mate. The range of inte...

Research paper thumbnail of The Status and Characterization of Enteroramus dimorphus: A Xylose-Fermenting Yeast Attached to the Gut of Beetles

Research paper thumbnail of Preserving Accuracy in GenBank

Research paper thumbnail of Phylogenetic Distribution of Fungal Sterols

Research paper thumbnail of Five novel Candida species in insect-associated yeast clades isolated from Neuroptera and other insects

Mycologia, 2007

Ascomycete yeasts are found commonly in the guts of basidioma-feeding beetles but little is known... more Ascomycete yeasts are found commonly in the guts of basidioma-feeding beetles but little is known about their occurrence in the gut of other insects. In this study we isolated 95 yeasts from the gut of adult insects in five neuropteran families (Neuroptera: Corydalidae, Chrysopidae, Ascalaphidae, Mantispidae and Hemerobiidae) and a roach (Blattodea: Blattidae). Based on DNA sequence comparisons and other taxonomic characteristics, they were identified as more than 15 species of Saccharomycetes as well as occasional Cryptococcus-like basidiomycete yeasts. Yeast species such as Lachancea fermentati, Lachancea thermotolerans and Hanseniaspora vineae were isolated repeatedly from the gut of three species of corydalids, suggesting a close association of these species and their insect hosts. Among the yeasts isolated in this study 12 were identified as five novel Candida species that occurred in three phylogenetically distinct clades. Molecular phylogenetic analyses showed that Candida chauliodes sp. nov. (NRRL Y-27909T) and Candida corydali sp. nov. (NRRL Y-27910T) were sister taxa in the Candida albicans/ Lodderomyces elongisporus clade. Candida dosseyi sp. nov. (NRRL Y-27950T) and Candida blattae sp. nov. (NRRL Y-27698T) were sister taxa in the Candida intermedia clade. Candida ascalaphidarum sp. nov. (NRRL Y-27908T) fell on a basal branch in a clade containing Candida membranifaciens and many other insect-associated species. Descriptions of these novel yeast species are provided as well as discussion of their ecology in relation to their insect hosts.

Research paper thumbnail of Phylogenetics of Saccharomycetales, the ascomycete yeasts

Research paper thumbnail of Phylogeny of Asexual Fungi Associated with Bark and Ambrosia Beetles

Research paper thumbnail of Distribution and sporulation phenology of myxomycetes in the Sonoran Desert of Arizona

Microbial Ecology, 1984

All pith samples from 68 dead saguaro cacti in 3 plots and 11 isolated dead plants in Saguaro Nat... more All pith samples from 68 dead saguaro cacti in 3 plots and 11 isolated dead plants in Saguaro National Monument, Arizona, produced at least one species of myxomycete upon incubation at 20 or 30°C. Three species,Badhamia gracilis (Macbr.) Macbr.,Physarum straminipes Lister, andDidymium eremophilum M. Blackwell et Gilbertson, developed at high frequencies on the substrates in moist chamber culture.Perichaena corticalis (Batsch) Rost, andProtophysarum phloiogenum M. Blackwell et Alexopoulos were also present. Although previous literature reports [9] indicated that Myxomycetes grow best at low pH, these species all tolerated substrates of pH 8.7-10.4.Didymium eremophilum andP. phloiogenum had peaks in sporulation within 6 days; other species were slower. There was no difference in time of sporulation ofB. gracilis orD. eremophilum at 20 and 30°C; however, sporulation ofP. straminipes was significantly later at 30°C. Reduced spore germination and slower buildup of critically sized amoebal populations ofP. straminipes at 30°C may be a factor.

Research paper thumbnail of A Group I Intron in the Nuclear Small Subunit rRNA Gene of Cryptendoxyla hypophloia, an Ascomycetous Fungus: Evidence for a New Major Class of Group I Introns

Journal of Molecular Evolution, 1999

Research paper thumbnail of Morphological and ecological similarities: wood-boring beetles associated with novel xylose-fermenting yeasts, Spathaspora passalidarum gen. sp. nov. and Candida jeffriesii sp. nov

Mycological Research, 2006

Ascomycete yeasts that both ferment and assimilate xylose were reported previously as associates ... more Ascomycete yeasts that both ferment and assimilate xylose were reported previously as associates of insects living in woody substrates. Most notable have been reports of Pichia stipitis-like yeasts that are widely associated with the wood-boring beetle, Odontotaenius disjunctus (Coleoptera: Passalidae), in the eastern United States. Our continuing investigation of insect gut yeasts has lead to the discovery of two new xylose-fermenting yeasts that phylogenetic analysis places as sister taxa. The beetle hosts, O. disjunctus and Phrenapates bennetti (Coleoptera: Tenebrionidae), are similar in habitat and appearance, and the presence of similar gut yeasts is an additional common feature between them. Here we describe the new yeast genus Spathaspora, the type species S. passalidarum, and its sister taxon Candida jeffriesii and discuss their natural history, including a comparison with Pichia stipitis, another member of a guild of xylose-fermenting yeasts with similar metabolic traits. In addition a morphologically distinct yeast ascospore type is described for Spathaspora.

Research paper thumbnail of Molecular data support the Laboulbeniales as a separate class of Ascomycota, Laboulbeniomycetes

Mycological Research, 2001

The Laboulbeniales have had a clouded taxonomic history. Initially interpreted as abnormal cuticu... more The Laboulbeniales have had a clouded taxonomic history. Initially interpreted as abnormal cuticular outgrowths of arthropods, they have since been considered to be acanthocephalans, basidiomycetes, and zygomycetes as well as ascomycetes. ...

Research paper thumbnail of Ascospores of Pyxidiophora on mites associated with beetles in trees and wood

Mycological Research, 1989

Research paper thumbnail of Metschnikowia noctiluminum sp. nov., Metschnikowia corniflorae sp. nov., and Candida chrysomelidarum sp. nov., isolated from green lacewings and beetles

Mycological Research, 2006

Fourteen yeast isolates belonging to the Metschnikowia clade were isolated from the digestive tra... more Fourteen yeast isolates belonging to the Metschnikowia clade were isolated from the digestive tracts of lacewings (Neuroptera: Chrysopidae), soldier beetles and leaf beetles (Coleoptera: Cantharidae and Chrysomelidae), and a caddisfly (Trichoptera: Hydropsychidae). The insect hosts were associated with sugary substances of plants, a typical habitat for yeasts in this clade. Based on DNA sequence comparisons and phenetic characters, the yeasts were identified as Candida picachoensis, Candida pimensis, and four undescribed taxa. Among the undescribed taxa, three yeasts were distinguished from one another and from other described taxa by nucleotide differences in the ribosomal DNA repeat, which were sufficient to consider them as new species. Two of the novel yeast species are described as Metschnikowia noctiluminum (NRRL Y-27753(T)) and M. cornifloraespp. nov. (NRRL Y-27750(T)) based in part on production of needle-shaped ascospores, which are found in most Metschnikowia species. Sexual reproduction was not observed in the third new yeast, Candida chrysomelidarumsp. nov. (NRRL Y-27749(T)). A fourth isolate, NRRL Y-27752, was not significantly distinct from Metschnikowia viticola and Candida kofuensis to be described as a new species. Phylogenetic analysis of the D1/D2 loop sequences placed M. noctiluminum within the M. viticola clade, while C. chrysomelidarum was a sister taxon of Candida rancensis. Metschnikowia corniflorae was phylogenetically distinct from other new species and fell outside of the large-spored Metschnikowia group.

Research paper thumbnail of The polyphyletic origins of ophiostomatoid fungi

Mycological Research, 1994

... 1-9 (1994) Printed in Great Britain I The polyphyletic origins of ophiostomatoid fungi JOSEPH... more ... 1-9 (1994) Printed in Great Britain I The polyphyletic origins of ophiostomatoid fungi JOSEPH W. SPATAFORA* AND MEREDITH BLACKWELL Department ... 1951; Hunt, 1956; Olchowecki & Reid, 1974; Upadhyay, 1981), in different families of the same order (de Hoog, 1974; von ...

Research paper thumbnail of Marchandiobasidium aurantiacum gen. sp. nov., the teleomorph of Marchandiomyces aurantiacus (Basidiomycota, Ceratobasidiales)

Mycological Research, 2003

Research paper thumbnail of Three new beetle-associated yeast species in the clade

FEMS Yeast Research, 2004

Research paper thumbnail of Fungal evolution and taxonomy

BioControl, 2009

Fungi and insects are closely associated in many terrestrial and some aquatic habitats. In additi... more Fungi and insects are closely associated in many terrestrial and some aquatic habitats. In addition to the pathogenic associations, many more interactions involve fungal spore dispersal. Recent advances in the study of insect-associated fungi have come from phylogenic analyses with increased taxon sampling and additional DNA loci. In addition to providing stable phylogenies, some molecular studies have begun to unravel