6 research outputs found
Multi-gene phylogenies define Ceratocystiopsis and Grosmannia distinct from Ophiostoma
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
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
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