scispace - formally typeset
Search or ask a question
Author

Alex Weir

Bio: Alex Weir is an academic researcher from State University of New York at Purchase. The author has contributed to research in topics: Laboulbeniales & Laboulbenia. The author has an hindex of 12, co-authored 25 publications receiving 2332 citations. Previous affiliations of Alex Weir include Natural History Museum & American Museum of Natural History.

Papers
More filters
Journal ArticleDOI
TL;DR: A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community.

2,096 citations

Journal ArticleDOI
TL;DR: The pattern of host utilization in the relatively fully-inventoried assemblage of beetles of a tropical forest in North Sulawesi is described, in terms of the taxonomic group membership, habitat affiliation and feeding biology of recorded hosts.
Abstract: Fungi of the order Laboulbeniales are obligate ectoparasites that are easy to detect on the integument of their arthropod hosts. This apparency, and other characteristics that suit them for the role of ‘model’ group in the exploration of parasite biodiversity patterns, are discussed. Salient features of the general biology of these organisms are summarized and past patterns of species description reviewed. In recent years, much as in the fungi as a whole, roughly equal proportions of new species have been described from tropical and temperate regions. Comparison of the known Laboulbeniales mycobiotas of Europe, Asia and ‘tropical Asia’ reveals that most of the more significant parasite genera are more or less equally well represented in each region. Patterns of host utilization are also largely similar, with more than 50% of host species recorded from each region belonging to the two beetle families Carabidae and Staphylinidae. However, there are indications that parasite species that are not confined to a single host species have significantly broader geographical ranges than any of their hosts. The pattern of host utilization in the relatively fully-inventoried assemblage of beetles of a tropical forest in North Sulawesi is described, in terms of the taxonomic group membership, habitat affiliation and feeding biology of recorded hosts. On the basis of the Sulawesi dataset and other available data on host exploitation patterns at various spatial scales, we suggest that between 2 and 5%, i.e. between ca 40000 and ca 100000 of an estimated 2 million extant beetle species, are hosts of one or more species of Laboulbeniales. Known and predicted levels of host specificity imply that a global figure for Laboulbeniales species exploiting Coleoptera is likely to be between 10000 and 50000 species. A smaller number of Laboulbeniales species, probably no more than half the number associated with beetles, are to be found on other arthropod hosts. Ways in which these estimates might be refined are discussed.

101 citations

Journal ArticleDOI
TL;DR: The morphological development of Hesperomyces virescens (Laboulbeniales) parasitic on the ladybird beetles Adalia bipunctata and Olla v-nigrum [Coleoptera, Coccinellidae] was studied by correlative studies.
Abstract: The morphological development of Hesperomyces virescens (Laboulbeniales) parasitic on the ladybird beetles Adalia bipunctata and Olla v-nigrum [Coleoptera, Coccinellidae] was studied by correlative...

45 citations

Journal ArticleDOI
TL;DR: Phylogenetic analysis of partial sequences of SSU rDNA with species of Chytridiomycota as outgroup taxa, and including trichomycete and entomophthoralean ZygomyCota, provides evidence of the placement of a Laboulbeniales-Pyxidiophora clade among the Ascomycota.

40 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community.

2,096 citations

Journal ArticleDOI
TL;DR: During evolution, the genetic programme for AM has been recruited for other plant root symbioses: functional adaptation of a plant receptor kinase that is essential for AM symbiosis paved the way for nitrogen-fixing bacteria to form intracellular symbiosis with plant cells.
Abstract: Arbuscular mycorrhiza (AM), a symbiosis between plants and members of an ancient phylum of fungi, the Glomeromycota, improves the supply of water and nutrients, such as phosphate and nitrogen, to the host plant. In return, up to 20% of plant-fixed carbon is transferred to the fungus. Nutrient transport occurs through symbiotic structures inside plant root cells known as arbuscules. AM development is accompanied by an exchange of signalling molecules between the symbionts. A novel class of plant hormones known as strigolactones are exuded by the plant roots. On the one hand, strigolactones stimulate fungal metabolism and branching. On the other hand, they also trigger seed germination of parasitic plants. Fungi release signalling molecules, in the form of 'Myc factors' that trigger symbiotic root responses. Plant genes required for AM development have been characterized. During evolution, the genetic programme for AM has been recruited for other plant root symbioses: functional adaptation of a plant receptor kinase that is essential for AM symbiosis paved the way for nitrogen-fixing bacteria to form intracellular symbioses with plant cells.

1,688 citations

Journal ArticleDOI
TL;DR: The number of known species of fungi is estimated as at least 74 K, but could be as much as 120 K with allowances for ‘orphaned’ species as discussed by the authors, which is the current working hypothesis for the number of fungi on Earth.

1,444 citations

Journal ArticleDOI
TL;DR: This revision of the classification of eukaryotes retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees.
Abstract: This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information.

1,414 citations

Journal ArticleDOI
TL;DR: Technological advances make it possible to apply molecular methods to develop a stable classification and to discover and identify fungal taxa, revealing a monophyletic kingdom and increased diversity among early-diverging lineages.
Abstract: Premise of the study Fungi are major decomposers in certain ecosystems and essential associates of many organisms. They provide enzymes and drugs and serve as experimental organisms. In 1991, a landmark paper estimated that there are 1.5 million fungi on the Earth. Because only 70000 fungi had been described at that time, the estimate has been the impetus to search for previously unknown fungi. Fungal habitats include soil, water, and organisms that may harbor large numbers of understudied fungi, estimated to outnumber plants by at least 6 to 1. More recent estimates based on high-throughput sequencing methods suggest that as many as 5.1 million fungal species exist. Methods Technological advances make it possible to apply molecular methods to develop a stable classification and to discover and identify fungal taxa. Key results Molecular methods have dramatically increased our knowledge of Fungi in less than 20 years, revealing a monophyletic kingdom and increased diversity among early-diverging lineages. Mycologists are making significant advances in species discovery, but many fungi remain to be discovered. Conclusions Fungi are essential to the survival of many groups of organisms with which they form associations. They also attract attention as predators of invertebrate animals, pathogens of potatoes and rice and humans and bats, killers of frogs and crayfish, producers of secondary metabolites to lower cholesterol, and subjects of prize-winning research. Molecular tools in use and under development can be used to discover the world's unknown fungi in less than 1000 years predicted at current new species acquisition rates.

1,094 citations