6 research outputs found

    Multi-gene phylogenies define Ceratocystiopsis and Grosmannia distinct from Ophiostoma

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    Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However, these species are retained in Ophiostoma until further data for a larger number of species can be obtained to confirm monophyly of the apparent lineages

    First fungal genome sequence from Africa : a preliminary analysis

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    Some of the most significant breakthroughs in the biological sciences this century will emerge from the development of next generation sequencing technologies. The ease of availability of DNA sequence made possible through these new technologies has given researchers opportunities to study organisms in a manner that was not possible with Sanger sequencing. Scientists will, therefore, need to embrace genomics, as well as develop and nurture the human capacity to sequence genomes and utilise the ’tsunami‘ of data that emerge from genome sequencing. In response to these challenges, we sequenced the genome of Fusarium circinatum, a fungal pathogen of pine that causes pitch canker, a disease of great concern to the South African forestry industry. The sequencing work was conducted in South Africa, making F. circinatum the first eukaryotic organism for which the complete genome has been sequenced locally. Here we report on the process that was followed to sequence, assemble and perform a preliminary characterisation of the genome. Furthermore, details of the computer annotation and manual curation of this genome are presented. The F. circinatum genome was found to be nearly 44 million bases in size, which is similar to that of four other Fusarium genomes that have been sequenced elsewhere. The genome contains just over 15 000 open reading frames, which is less than that of the related species, Fusarium oxysporum, but more than that for Fusarium verticillioides. Amongst the various putative gene clusters identified in F. circinatum, those encoding the secondary metabolites fumosin and fusarin appeared to harbour evidence of gene translocation. It is anticipated that similar comparisons of other loci will provide insights into the genetic basis for pathogenicity of the pitch canker pathogen. Perhaps more importantly, this project has engaged a relatively large group of scientists including students in a significant genome project that is certain to provide a platform for growth in this important area of research in the future.We thank the National Research Foundation (NRF) of South Africa, members of the Tree Protection Co-operative Programme, the THRIP initiative of the Department of Trade and Industry and the Department of Science and Technology (DST)/NRF Centre of Excellence in Tree Health Biotechnology and the Oppenheimer Foundation for funding.http://www.sajs.co.zanf201

    First fungal genome sequence from Africa: A preliminary analysis

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    Some of the most significant breakthroughs in the biological sciences this century will emerge from the development of next generation sequencing technologies. The ease of availability of DNA sequence made possible through these new technologies has given researchers opportunities to study organisms in a manner that was not possible with Sanger sequencing. Scientists will, therefore, need to embrace genomics, as well as develop and nurture the human capacity to sequence genomes and utilise the ’tsunami‘ of data that emerge from genome sequencing. In response to these challenges, we sequenced the genome of Fusarium circinatum, a fungal pathogen of pine that causes pitch canker, a disease of great concern to the South African forestry industry. The sequencing work was conducted in South Africa, making F. circinatum the first eukaryotic organism for which the complete genome has been sequenced locally. Here we report on the process that was followed to sequence, assemble and perform a preliminary characterisation of the genome. Furthermore, details of the computer annotation and manual curation of this genome are presented. The F. circinatum genome was found to be nearly 44 million bases in size, which is similar to that of four other Fusarium genomes that have been sequenced elsewhere. The genome contains just over 15 000 open reading frames, which is less than that of the related species, Fusarium oxysporum, but more than that for Fusarium verticillioides. Amongst the various putative gene clusters identified in F. circinatum, those encoding the secondary metabolites fumosin and fusarin appeared to harbour evidence of gene translocation. It is anticipated that similar comparisons of other loci will provide insights into the genetic basis for pathogenicity of the pitch canker pathogen. Perhaps more importantly, this project has engaged a relatively large group of scientists including students in a significant genome project that is certain to provide a platform for growth in this important area of research in the future

    V. Anhang

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