5 results on '"King, Robert"'
Search Results
2. Inter-genome comparison of the Quorn fungus Fusarium venenatum and the closely related plant infecting pathogen Fusarium graminearum
- Author
-
King, Robert, Brown, Neil Andrew, Urban, Martin, and Hammond-Kosack, Kim E.
- Published
- 2018
- Full Text
- View/download PDF
3. Inter-genome comparison of the Quorn fungus <italic>Fusarium venenatum</italic> and the closely related plant infecting pathogen <italic>Fusarium graminearum</italic>.
- Author
-
King, Robert, Brown, Neil Andrew, Urban, Martin, and Hammond-Kosack, Kim E.
- Subjects
FUSARIUM ,GENOMES ,PHYTOPATHOGENIC microorganisms ,METABOLITES ,MITOCHONDRIAL DNA ,HYDROLASES - Abstract
Background: The soil dwelling saprotrophic non-pathogenic fungus
Fusarium venenatum , routinely used in the commercial fermentation industry, is phylogenetically closely related to the globally important cereal and non-cereal infecting pathogenF. graminearum . This study aimed to sequence, assemble and annotate theF. venenatum (strain A3/5) genome, and compare this genome withF. graminearum . Results: Using shotgun sequencing, a 38,660,329 bpF. venenatum genome was assembled into four chromosomes, and a 78,618 bp mitochondrial genome. In comparison toF. graminearum , the predicted gene count of 13,946 was slightly lower. TheF. venenatum centromeres were found to be 25% smaller compared toF. graminearum . Chromosome length was 2.8% greater inF. venenatum, primarily due to an increased abundance of repetitive elements and transposons, but not transposon diversity. On chromosome 3 a major sequence rearrangement was found, but its overall gene content was relatively unchanged. Unlike homothallicF. graminearum , heterothallicF. venenatum possessed theMAT1–1 type locus, but lacked theMAT1–2 locus. TheF. venenatum genome has the type A trichothecene mycotoxinTRI5 cluster, whereasF. graminearum has type B. From theF. venenatum gene set, 786 predicted proteins were species-specific versus NCBI. The annotatedF. venenatum genome was predicted to possess more genes coding for hydrolytic enzymes and species- specific genes involved in the breakdown of polysaccharides thanF. graminearum . Comparison of the two genomes reduced the previously definedF. graminearum- specific gene set from 741 to 692 genes. A comparison of theF. graminearum versusF. venenatum proteomes identified 15 putative secondary metabolite gene clusters (SMC), 109 secreted proteins and 38 candidate effectors not found inF. venenatum . Five of the 15F. graminearum-specific SMCs that were either absent or highly divergent in theF. venenatum genome showed increased in planta expression. In addition, two predictedF. graminearum transcription factors previously shown to be required for fungal virulence on wheat plants were absent or exhibited high sequence divergence. Conclusions: This study identifies differences between theF. venenatum andF. graminearum genomes that may contribute to contrasting lifestyles, and highlights the repertoire ofF. graminearum -specific candidate genes and SMCs potentially required for pathogenesis. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
4. The completed genome sequence of the pathogenic ascomycete fungus Fusarium graminearum.
- Author
-
King, Robert, Urban, Martin, Hammond-Kosack, Michael C. U., Hassani-Pak, Keywan, and Hammond-Kosack, Kim E.
- Subjects
- *
FUSARIUM genetics , *FUNGAL genomes , *FUNGAL virulence , *ASCOMYCETES , *RNA sequencing , *SEQUENCE alignment , *GIBBERELLA zeae - Abstract
Background: Accurate genome assembly and gene model annotation are critical for comparative species and gene functional analyses. Here we present the completed genome sequence and annotation of the reference strain PH-1 of Fusarium graminearum, the causal agent of head scab disease of small grain cereals which threatens global food security. Completion was achieved by combining (a) the BROAD Sanger sequenced draft, with (b) the gene predictions from Munich Information Services for Protein Sequences (MIPS) v3.2, with (c) de novo whole-genome shotgun re-sequencing, (d) re-annotation of the gene models using RNA-seq evidence and Fgenesh, Snap, GeneMark and Augustus prediction algorithms, followed by (e) manual curation. Results: We have comprehensively completed the genomic 36,563,796 bp sequence by replacing unknown bases, placing supercontigs within their correct loci, correcting assembly errors, and inserting new sequences which include for the first time complete AT rich sequences such as centromere sequences, subtelomeric regions and the telomeres. Each of the four F. graminearium chromosomes was found to be submetacentric with respect to centromere positioning. The position of a potential neocentromere was also defined. A preferentially higher frequency of genetic recombination was observed at the end of the longer arm of each chromosome. Within the genome 1529 gene models have been modified and 412 new gene models predicted, with a total gene call of 14,164. The re-annotation impacts upon 69 entries held within the Pathogen-Host Interactions database (PHI-base) which stores information on genes for which mutant phenotypes in pathogen-host interactions have been experimentally tested, of which 59 are putative transcription factors, 8 kinases, 1 ATP citrate lyase (ACL1), and 1 syntaxin-like SNARE gene (GzSYN1). Although the completed F. graminearum contains very few transposon sequences, a previously unrecognised and potentially active gypsy-type long-terminal-repeat (LTR) retrotransposon was identified. In addition, each of the sub-telomeres and centromeres contained either a LTR or MarCry-1_FO element. The full content of the proposed ancient chromosome fusion sites has also been revealed and investigated. Regions with high recombination previously noted to be rich in secretome encoding genes were also found to be rich in tRNA sequences. This study has identified 741 F. graminearum species specific genes and provides the first complete genome assembly for a Sordariomycetes species. Conclusions: This fully completed F. graminearum PH-1 genome and manually curated annotation, available at Ensembl Fungi, provides the optimum resource to perform interspecies comparative analyses and gene function studies. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
5. Whole-genome analysis of Fusarium graminearum insertional mutants identifies virulence associated genes and unmasks untagged chromosomal deletions.
- Author
-
Urban, Martin, King, Robert, Hassani-Pak, Keywan, and Hammond-Kosack, Kim E.
- Subjects
- *
PATHOGENIC microorganisms , *PLASMID genetics , *NUCLEOTIDE sequence , *GENE amplification ,WHEAT genetics - Abstract
Background: Identifying pathogen virulence genes required to cause disease is crucial to understand the mechanisms underlying the pathogenic process. Plasmid insertion mutagenesis of fungal protoplasts is frequently used for this purpose in filamentous ascomycetes. Post transformation, the mutant population is screened for loss of virulence to a specific plant or animal host. Identifying the insertion event has previously met with varying degrees of success, from a cleanly disrupted gene with minimal deletion of nucleotides at the insertion point to multiple-copy insertion events and large deletions of chromosomal regions. Currently, extensive mutant collections exist in laboratories globally where it was hitherto impossible to identify all the affected genes. Results: We used a whole-genome sequencing (WGS) approach using Illumina HiSeq 2000 technology to investigate DNA tag insertion points and chromosomal deletion events in mutagenised, reduced virulence F. graminearum isolates identified in disease tests on wheat (Triticum aestivum). We developed the FindInsertSeq workflow to localise the DNA tag insertions to the nucleotide level. The workflow was tested using four mutants showing evidence of single and multi-copy insertions in DNA blot analysis. FindInsertSeq was able to identify both single and multi-copy concatenation insertion sites. By comparing sequencing coverage, unexpected molecular recombination events such as large tagged and untagged chromosomal deletions, and DNA amplification were observed in three of the analysed mutants. A random data sampling approach revealed the minimum genome coverage required to survey the F. graminearum genome for alterations. Conclusions: This study demonstrates that whole-genome re-sequencing to 22x fold genome coverage is an efficient tool to characterise single and multi-copy insertion mutants in the filamentous ascomycete Fusarium graminearum. In some cases insertion events are accompanied with large untagged chromosomal deletions while in other cases a straight-forward insertion event could be confirmed. The FindInsertSeq analysis workflow presented in this study enables researchers to efficiently characterise insertion and deletion mutants. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.