Fungal Model Organisms Research Articles

Neolecta—a fungal dinosaur? Evidence from β-tubulin amino acid sequences

Were the first ascomycetes yeast-like (unicellular) or filamentous with complex multicellular growth? Molecular studies have indicated that the earliest lineages of ascomycetes were mostly yeast-like and without complex, multicellular fruit bodies. The genus Neolecta stands out as an exception. Neolecta spp. have filamentous growth and discomycete-type of fruit bodies, but constitute one of the basal lineages both in rRNA and RPB2 gene trees. In this paper, we have used 10 previously unpublished and 30 GenBank β-tubulin genes to test the phylogenetic position of Neolecta spp. We compared the phylogenetic information from the amino acid sequences (485 characters) with the phylogenetic information content of 33 characters from intron gains and losses. Due to gene duplications, two paralogous versions of β-tubulin genes occurred in four species included in our analysis. Although phylogenetic interpretation of β-tubulin gene trees was complicated by a history of gene duplications, intron gains and losses, and by unequal rates of amino acid substitution, Neolecta species never formed a monophyletic group with any of the sequences from the filamentous ascomycetes in the Pezizomycotina (euascomycetes) in parsimony or distance analyses. Like the RPB2 and rRNA genes, the β-tubulin genes support the hypotheses of an early divergence of Neolecta from superficially similar filamentous ascomycetes. Neolecta could become a key taxon particularly in comparative studies between the fungal model organisms in the mainly unicellular (=yeast-like) taxa Saccharomyces and Schizosaccharomyces and the filamentous fruit-body forming taxa Neurospora and Aspergillus.

Fungal Model Organisms: Phylogenetics of Saccharomyces, Aspergillus, and Neurospora

Fungal model organisms are widely used because, in general, they are less expensive to maintain under laboratory conditions than are members of the two other higher eukaryotic kingdoms, the animals and plants. Ascomycetes have been the most popular fungi with geneticists and molecular developmental biologists, beginning with Neurospora and recently with Saccharomyces and Aspergillus. Fungal molecular evolution studies of 18S ribosomal RNA and DNA have recently produced a robust phylogeny of ascomycetes, and molecular genetic studies of fungal development are unraveling the pathway of spore production. We wondered if systematists and developmental biologists were taking advantage of each other's knowledge. The majority of molecular biology studies of fungi still use model species, and only a few studies of nonmodel organisms have used phylogenetic information in their design. Likewise, studies of asexual spore development and mating type genes have emphasized model fungi, but studies of mating type in nonmodel fungi are beginning to yield results. We predict that truly comparative molecular biological studies of fungal development will be available shortly because the prerequisites have been completed, e.g., a well-supported phylogeny, sophisticated molecular techniques, including complementation by transformation and gene disruption, and morphological developmental pathways that are simpler than those of plants or animals.

Fungal Model Organisms: Phylogenetics of Saccharomyces, Aspergillus, and Neurospora

Fungal model organisms are widely used because, in general, they are less expensive to maintain under laboratory conditions than are members of the two other higher eukaryotic kingdoms, the animals and plants. Ascomycetes have been the most popular fungi with geneticists and molecular developmental biologists, beginning with Neurospora and recently with Saccharomyces and Aspergillus. Fungal molecular evolution studies of 18S ribosomal RNA and DNA have recently produced a robust phylogeny of ascomycetes, and molecular genetic studies of fungal development are unraveling the pathway of spore production. We wondered if systematists and developmental biologists were taking advantage of each other's knowledge. The majority of molecular biology studies of fungi still use model species, and only a few studies of nonmodel organisms have used phylogenetic information in their design. Likewise, studies of asexual spore development and mating type genes have emphasized model fungi, but studies of mating type in nonmodel fungi are beginning to yield results. We predict that truly comparative molecular biological studies of fungal development will be available shortly because the prerequisites have been completed, e.g., a well-supported phylogeny, sophisticated molecular techniques, including complementation by transformation and gene disruption, and morphological developmental pathways that are simpler than those of plants or animals.

Vegetable Ferments

Previous articleNext article FreeNoteworthy Anatomical and Physiological ResearchesVegetable FermentsJ. Christian BayJ. Christian Bay Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 19, Number 2Feb., 1894 Article DOIhttps://doi.org/10.1086/327016 Views: 5 Citations: 1Citations are reported from Crossref Journal History This article was published in the Botanical Gazette (1876-1991), which is continued by International Journal of Plant Sciences (1992-present). PDF download Crossref reports the following articles citing this article:Kevin McCluskey, Scott E. Baker Diverse data supports the transition of filamentous fungal model organisms into the post-genomics era, Mycology 8, no.22 (Feb 2017): 67–83.https://doi.org/10.1080/21501203.2017.1281849