ABSTRACT: Powdery mildew (Erysiphe necator) is a widespread and economically important disease of grapevines. Large quantities of fungicides are used for its control, accelerating the incidence of fungicide-resistance. A shotgun approach was applied to sequence and assemble the E. necator genome of five isolates, and RNA-seq and comparative genomics were used to predict and annotate protein-coding genes. In addition, a collection of 98 E. necator isolates collected from diverse locations was used for SSR profiling and was screened for copy number variation and presence/absence of a single point mutation (Y136F) in the CYP51 gene, a key target for DMI fungicides. Our results show that the E. necator genome is exceptionally large and repetitive and suggests that transposable elements are responsible for genome expansion. Frequent structural variations were found between isolates and included copy number variant (CNV) in CYP51. We show that CYP51 copy number correlates with expression level and that an increase in copy number is detected in isolates collected from fungicide-treated vineyards. This copy number variation was usually detected with the CYP51 mutant allele (Y136F), suggesting that an increase in copy number becomes advantageous only when the allele is mutated. We also show that CYP51 copy number correlates with fungal growth in the presence of DMI fungicide in vitro. These results suggest that copy number variation can be adaptive in the development of resistance to DMI fungicides in E. necator.
Project description:Powdery mildew (Erysiphe necator) is a widespread and economically important disease of grapevines. Large quantities of fungicides are used for its control, accelerating the incidence of fungicide-resistance. A shotgun approach was applied to sequence and assemble the E. necator genome of five isolates, and RNA-seq and comparative genomics were used to predict and annotate protein-coding genes. In addition, a collection of 98 E. necator isolates collected from diverse locations was used for SSR profiling and was screened for copy number variation and presence/absence of a single point mutation (Y136F) in the CYP51 gene, a key target for DMI fungicides. Our results show that the E. necator genome is exceptionally large and repetitive and suggests that transposable elements are responsible for genome expansion. Frequent structural variations were found between isolates and included copy number variant (CNV) in CYP51. We show that CYP51 copy number correlates with expression level and that an increase in copy number is detected in isolates collected from fungicide-treated vineyards. This copy number variation was usually detected with the CYP51 mutant allele (Y136F), suggesting that an increase in copy number becomes advantageous only when the allele is mutated. We also show that CYP51 copy number correlates with fungal growth in the presence of DMI fungicide in vitro. These results suggest that copy number variation can be adaptive in the development of resistance to DMI fungicides in E. necator. Detach Carignan leaves were sprayed with a Erysiphe necator C-strain conida suspension, leaves were collected in 4 time points (12 hours, 24 hours, 3 days, and 6 days) post inoculation. For each time point, two leaves from the same seedling were pooled and frozen in liquid nitrogen, and each time point was performed in triplicate.
Project description:Background: Copy number variation is an important component of genetic variation in higher eukaryotes. The extent of natural copy number variation in C. elegans is unknown outside of 2 highly divergent wild isolates and the canonical N2 Bristol strain. Results: We have used array comparative genomic hybridization (aCGH) to detect copy number variation in the genomes of 12 natural isolates of Caenorhabditis elegans. Deletions relative to the canonical N2 strain are more common in these isolates than duplications, and indels are enriched in multigene families on the autosome arms. Among the strains in our study, the Hawaiian and Madeiran strains (CB4856 and JU258) carry the largest number of deletions, followed by the Vancouver strain (KR314). Overall we detected 510 different deletions affecting 1136 genes, or over 5% of the genes in the canonical N2 genome. The indels we identified had a median length of 2.7 kb. Since many deletions are found in multiple isolates, deletion loci were used as markers to derive an unrooted tree to estimate genetic relatedness among the strains. Conclusion: Copy number variation is extensive in C. elegans, affecting over 5% of the genes in the genome. The deletions we have detected in natural isolates of C. elegans contribute significantly to the number of deletion alleles available to researchers. The relationships between strains are complex and different regions of the genome possess different genealogies due to recombination throughout the natural history of the species, which may not be apparent in studies utilizing smaller numbers of genetic markers.
Project description:This SuperSeries is composed of the following subset Series: GSE29627: Chromosome copy number variation in Cryptococcus neoformans influences virulence and occurs in isolates from AIDS patients: CBS7779 black and white strains GSE29671: Chromosome copy number variation in Cryptococcus neoformans influences virulence and occurs in isolates from AIDS patients: clinal and environmental strains Refer to individual Series
Project description:Background: Copy number variation is an important component of genetic variation in higher eukaryotes. The extent of natural copy number variation in C. elegans is unknown outside of 2 highly divergent wild isolates and the canonical N2 Bristol strain. Results: We have used array comparative genomic hybridization (aCGH) to detect copy number variation in the genomes of 12 natural isolates of Caenorhabditis elegans. Deletions relative to the canonical N2 strain are more common in these isolates than duplications, and indels are enriched in multigene families on the autosome arms. Among the strains in our study, the Hawaiian and Madeiran strains (CB4856 and JU258) carry the largest number of deletions, followed by the Vancouver strain (KR314). Overall we detected 510 different deletions affecting 1136 genes, or over 5% of the genes in the canonical N2 genome. The indels we identified had a median length of 2.7 kb. Since many deletions are found in multiple isolates, deletion loci were used as markers to derive an unrooted tree to estimate genetic relatedness among the strains. Conclusion: Copy number variation is extensive in C. elegans, affecting over 5% of the genes in the genome. The deletions we have detected in natural isolates of C. elegans contribute significantly to the number of deletion alleles available to researchers. The relationships between strains are complex and different regions of the genome possess different genealogies due to recombination throughout the natural history of the species, which may not be apparent in studies utilizing smaller numbers of genetic markers. Twelve C. elegans natural isolate samples were studied. There were no replicates or dye-swap hybridizations.
Project description:Resistance to agricultural fungicides in the field has created a need for discovering fungicides with new modes of action. DNA microarrays, because they provide information on expression of many genes simultaneously, could help to identify the modes of action. To begin an expression pattern database for agricultural fungicides, transcriptional patterns of Saccharomyces cerevisiae strain S288C genes were analysed following 2-h treatments with I50 concentrations of ergosterol biosynthesis inhibitors commonly used against plant pathogenic fungi. Eight fungicides, representing three classes of ergosterol biosynthesis inhibitors, were tested. To compare gene expression in response to a fungicide with a completely different mode of action, a putative methionine biosynthesis inhibitor (MBI) was also tested. Expression patterns of ergosterol biosynthetic genes supported the roles of Class I and Class II inhibitors in affecting ergosterol biosynthesis, confirmed that the putative MBI did not affect ergosterol biosynthesis, and strongly suggested that in yeast, the Class III inhibitor did not affect ergosterol biosynthesis. The MBI affected transcription of three genes involved in methionine metabolism, whereas there were essentially no effects of ergosterol synthesis inhibitors on methionine metabolism genes. There were no consistent patterns in other up- or downregulated genes between fungicides. These results suggest that inspection of gene response patterns within a given pathway may serve as a useful first step in identifying possible modes of action of fungicides. agricultural sterol biosynthesis inhibitor fungicides. Keywords = agriculture Keywords = ergosterol Keywords = methionine Keywords = fungicide Keywords = Saccharomyces cerevisiae S288C Keywords = biosynthesis
Project description:Resistance to agricultural fungicides in the field has created a need for discovering fungicides with new modes of action. DNA microarrays, because they provide information on expression of many genes simultaneously, could help to identify the modes of action. To begin an expression pattern database for agricultural fungicides, transcriptional patterns of Saccharomyces cerevisiae strain S288C genes were analysed following 2-h treatments with I50 concentrations of ergosterol biosynthesis inhibitors commonly used against plant pathogenic fungi. Eight fungicides, representing three classes of ergosterol biosynthesis inhibitors, were tested. To compare gene expression in response to a fungicide with a completely different mode of action, a putative methionine biosynthesis inhibitor (MBI) was also tested. Expression patterns of ergosterol biosynthetic genes supported the roles of Class I and Class II inhibitors in affecting ergosterol biosynthesis, confirmed that the putative MBI did not affect ergosterol biosynthesis, and strongly suggested that in yeast, the Class III inhibitor did not affect ergosterol biosynthesis. The MBI affected transcription of three genes involved in methionine metabolism, whereas there were essentially no effects of ergosterol synthesis inhibitors on methionine metabolism genes. There were no consistent patterns in other up- or downregulated genes between fungicides. These results suggest that inspection of gene response patterns within a given pathway may serve as a useful first step in identifying possible modes of action of fungicides. agricultural sterol biosynthesis inhibitor fungicides. Keywords = agriculture Keywords = ergosterol Keywords = methionine Keywords = fungicide Keywords = Saccharomyces cerevisiae S288C Keywords = biosynthesis
Project description:Phytophthora infestans, the causal agent of late blight disease of potatoes, is mainly controlled by the use of fungicides. Isolates that are resistant to commonly used fungicides have been reported. Also, several studies show that originally mefenoxam-sensitive isolates acquire resistance to this fungicide when exposed to sub-lethal concentrations. This phenomenon, termed ‘mefenoxam-acquired resistance’, has been observed in different Phytophthora species and seems to be unique to mefenoxam. In this study, we aimed to elucidate the molecular mechanism mediating this type of resistance as well as a possible regulatory process behind it. A combination of computational analyses and experimental approaches was used to identify differentially expressed genes with a potential association to the phenomenon. These genes were classified into seven functional groups. Most of them seem to be associated with a pleiotropic drug resistance (PDR) phenotype, typically involved in the expulsion of diverse metabolites, drugs, or other substances out of the cell. Despite the importance of RNApolI for the constitutive resistance of P. infestans to mefenoxam, our results indicate no clear interaction between this protein and the acquisition of mefenoxam resistance. Several small non-coding RNAs (ncRNAs) were found to be differentially expressed and specifically related to genes mediating the PDR phenotype, thus suggesting a possible regulatory process. We propose a model of the molecular mechanisms acting within the cell when P. infestans acquires resistance to mefenoxam after exposed to sub-lethal concentrations of the fungicide. This study provides important insights into P. infestans’ cellular and regulatory functionalities.
2021-12-01 | GSE186905 | GEO
Project description:copy number variation among silkworm