Submission Type
Oral Presentation
Abstract
Cereal grains (e.g. rice, wheat) comprise up to 50% of worldwide daily caloric intake. One fungal disease affecting these crops that exhibits high pathogenicity and virulence is blast disease. The pathogen is Pyricularia oryzae, a primarily asexual ascomycete fungus. Despite being primarily asexual P. oryzae has a wide host range and been documented to have high phenotypic and pathogenic variability, contradicting Muller’s rachet. It is postulated that other genetic mechanisms are being utilized to generate genome instability and, thus, genetic diversity, such as transposons. Recent findings suggest that a novel class of massive transposons (10kb - >300Kb), termed Starships, inserted into the 5sRNA genes of P. oryzae has allowed for massive structural genome rearrangements and evolution leading to phenotypic novelty and subsequent host expansion. The novel transposons referred to as Starships and their unique gene content are the focus of our research. The gene contents of twenty-one Starships from ten fungal strains were first identified through the gene prediction program Fgenesh. The protein predictions produced by Fgenesh were then compared to the NCBI protein database using the software program blastp. The blastp results suggest that the Starship fungal genes consist primarily of fungal secondary metabolite (e.g. sugar utilization) genes, with some predicted proteins exhibiting DNA binding properties. Current analyses suggest that the Pyricularia Starships serve as gene transport vectors, potentially relocating genes both within and potentially among different strain genomes.
Included in
Evidence for Starship transposons as facilitators of fungal genome evolution
Cereal grains (e.g. rice, wheat) comprise up to 50% of worldwide daily caloric intake. One fungal disease affecting these crops that exhibits high pathogenicity and virulence is blast disease. The pathogen is Pyricularia oryzae, a primarily asexual ascomycete fungus. Despite being primarily asexual P. oryzae has a wide host range and been documented to have high phenotypic and pathogenic variability, contradicting Muller’s rachet. It is postulated that other genetic mechanisms are being utilized to generate genome instability and, thus, genetic diversity, such as transposons. Recent findings suggest that a novel class of massive transposons (10kb - >300Kb), termed Starships, inserted into the 5sRNA genes of P. oryzae has allowed for massive structural genome rearrangements and evolution leading to phenotypic novelty and subsequent host expansion. The novel transposons referred to as Starships and their unique gene content are the focus of our research. The gene contents of twenty-one Starships from ten fungal strains were first identified through the gene prediction program Fgenesh. The protein predictions produced by Fgenesh were then compared to the NCBI protein database using the software program blastp. The blastp results suggest that the Starship fungal genes consist primarily of fungal secondary metabolite (e.g. sugar utilization) genes, with some predicted proteins exhibiting DNA binding properties. Current analyses suggest that the Pyricularia Starships serve as gene transport vectors, potentially relocating genes both within and potentially among different strain genomes.
Comments
Ciara Pike1, Emily Donaldson1, Raina Boggs1, Camden Ping1, Makayla Baker1, Patrick Calie1 and Mark Farman2.
1Department of Biological Sciences, Eastern Kentucky University, Richmond, KY
2Department of Plant Pathology, University of Kentucky, Lexington, KY