Project description:The barley powdery mildew effector (CSEP0491) dataset was part of a larger Y2H screen (GEO GSE150396) to identify novel proteins involved in barley immune responses. Yeast-two-hybrid (Y2H) screening was coupled with next-generation sequencing to identify and quantify interacting proteins. The CSEP0491 bait was mated to a cDNA prey library derived from a 0-48 hour time course of infected leaf tissue. Screens were performed in batch liquid culture to enrich yeast populations for cells expressing positive interactions. After two rounds of enrichment under selective (Histidine absent) and non-selective (Histidine present) conditions, yeast cells were collected. Y2H plasmids were extracted and prey cDNA amplicons were generated via low-cycle PCR. Fragmented amplicons were used as input to generate sequencing libraries and processed on the HiSeq 3000 platform. Reads were mapped to the barley and Blumeria graminis genomes and read counts were analyzed using a custom data processing and scoring pipeline. Putative interactors were cloned and binary Y2H was used to confirm interactions. Overall design: Y2H screening of a cDNA library was coupled to next-generation sequencing to identify and rank positive protein-protein interactions. Screening for the CSEP0491 bait was conducted in triplicate with yeast cells grown in selective and non-selective conditions. NuGEN’s AnyDeplete technology was used to deplete HORVU3Hr1G072260 (zinc finger protein) from the samples. Two constructs of luciferase were used as bait negative controls. Samples were run on three lanes of Illumina’s HiSeq 3000.
Project description:The barley powdery mildew avirulence effector (AVRA1) dataset was part of a larger Y2H screen (GEO GSE150396) to identify novel proteins involved in barley immune responses. Yeast-two-hybrid (Y2H) screening was coupled with next-generation sequencing to identify and quantify interacting proteins. An AVRA1 bait was mated to a cDNA prey library derived from a 0-48 hour time course of infected leaf tissue. Screens were performed in batch liquid culture to enrich yeast populations for cells expressing positive interactions. After two rounds of enrichment under selective (Histidine absent) and non-selective (Histidine present) conditions, yeast cells were collected. Y2H plasmids were extracted and prey cDNA amplicons were generated via low-cycle PCR. Fragmented amplicons were used as input to generate sequencing libraries and processed on the HiSeq 3000 platform. Reads were mapped to the barley and Blumeria graminis genomes and read counts were analyzed using a custom data processing and scoring pipeline. Putative interactors were cloned and binary Y2H was used to confirm interactions. Overall design: Y2H screening of a cDNA library was coupled to next-generation sequencing to identify and rank positive protein-protein interactions. Screening for the AVRA1 bait was conducted in triplicate with yeast cells grown in selective and non-selective conditions. NuGEN’s AnyDeplete technology was used to deplete HORVU3Hr1G072260 (zinc finger protein) from the samples. Two constructs of luciferase were used as bait negative controls. Samples were run on three lanes of Illumina’s HiSeq 3000.
Project description:Mapping-by-sequencing has emerged as a powerful technique for genetic mapping in several plant and animal species. As this resequencing-based method requires a reference genome, its application to complex plant genomes with incomplete and fragmented sequence resources remains challenging. We perform exome sequencing of phenotypic bulks of a mapping population of barley segregating for a mutant phenotype that increases the rate of leaf initiation. Read depth analysis identifies a candidate gene, which is confirmed by the analysis of independent mutant alleles. Our method illustrates how the genomic resources of barley together with exome resequencing can underpin mapping-by-sequencing.
Project description:BACKGROUND: Resequencing of deafness related genes using GS FLX massive parallel sequencing of PCR amplicons spanning selected genes has previously been reported as a successful strategy to discover causal variants. The amplicon lengths were designed to be smaller than the sequencing read length of GS FLX technology, but are longer than Illumina sequencing technology read lengths. Fragmentation is thus required to sequence these amplicons using high throughput Illumina technology. METHODS: We performed Illumina sequencing in 4 patients on 563 multiplexed amplicons covering the exons of 15 genes involved in the hearing process. After exploring several fragmentation strategies, the amplicons were fragmented using Covaris sonication prior to library preparation. CLC genomic workbench was used to analyze the data. RESULTS: We achieve an excellent coverage with more than 99% of the amplicons bases covered. All variants that were previously validated using Sanger sequencing, were also called in this study. Variant calling revealed less false positive and false negative results compared to the previous study. For each patient, several variants were found that are reported by ClinVar as possible hearing loss variants. CONCLUSION: Migration from GS FLX amplicon sequencing to Illumina amplicon sequencing is straightforward and leads to more accurate results.
Project description:Sequencing analysis of mitochondrial genomes is important for understanding the evolution and genome structures of various plant species. Barley is a self-pollinated diploid plant with seven chromosomes comprising a large haploid genome of 5.1 Gbp. Wild barley (Hordeum vulgare ssp. spontaneum) and cultivated barley (H. vulgare ssp. vulgare) have cross compatibility and closely related genomes, although a significant number of nucleotide polymorphisms have been reported between their genomes.We determined the complete nucleotide sequences of the mitochondrial genomes of wild and cultivated barley. Two independent circular maps of the 525,599 bp barley mitochondrial genome were constructed by de novo assembly of high-throughput sequencing reads of barley lines H602 and Haruna Nijo, with only three SNPs detected between haplotypes. These mitochondrial genomes contained 33 protein-coding genes, three ribosomal RNAs, 16 transfer RNAs, 188 new ORFs, six major repeat sequences and several types of transposable elements. Of the barley mitochondrial genome-encoded proteins, NAD6, NAD9 and RPS4 had unique structures among grass species.The mitochondrial genome of barley was similar to those of other grass species in terms of gene content, but the configuration of the genes was highly differentiated from that of other grass species. Mitochondrial genome sequencing is essential for annotating the barley nuclear genome; our mitochondrial sequencing identified a significant number of fragmented mitochondrial sequences in the reported nuclear genome sequences. Little polymorphism was detected in the barley mitochondrial genome sequences, which should be explored further to elucidate the evolution of barley.
Project description:Barley is a diploid species with a genome smaller than those of other members of the Triticeae tribe, making it an attractive model for genetic studies in Triticeae crops. The recent development of barley genomics has created a need for a high-throughput platform to identify genetically uniform mutants for gene function investigations. In this study, we report an ethyl methanesulfonate (EMS)-mutagenized population consisting of 8525 M<sub>3</sub> lines in the barley landrace "Hatiexi" (HTX), which we complement with a high-quality de novo assembly of a reference genome for this genotype. The mutation rate within the population ranged from 1.51 to 4.09 mutations per megabase, depending on the treatment dosage of EMS and the mutation discrimination platform used for genotype analysis. We implemented a three-dimensional DNA pooling strategy combined with multiplexed amplicon sequencing to create a highly efficient and cost-effective TILLING (targeting induced locus lesion in genomes) platform in barley. Mutations were successfully identified from 72 mixed amplicons within a DNA pool containing 64 individual mutants and from 56 mixed amplicons within a pool containing 144 individuals. We discovered abundant allelic mutants for dozens of genes, including the barley Green Revolution contributor gene Brassinosteroid insensitive 1 (BRI1). As a proof of concept, we rapidly determined the causal gene responsible for a chlorotic mutant by following the MutMap strategy, demonstrating the value of this resource to support forward and reverse genetic studies in barley.
Project description:BACKGROUND: MicroRNAs are important components of the regulatory network of biological systems and thousands have been discovered in both animals and plants. Systematic investigations performed in species with sequenced genomes such as Arabidopsis, rice, poplar and Brachypodium have provided insights into the evolutionary relationships of this class of small RNAs among plants. However, miRNAs from barley, one of the most important cereal crops, remain unknown. RESULTS: We performed a large scale study of barley miRNAs through deep sequencing of small RNAs extracted from leaves of two barley cultivars. By using the presence of miRNA precursor sequences in related genomes as one of a number of supporting criteria, we identified up to 100 miRNAs in barley. Of these only 56 have orthologs in wheat, rice or Brachypodium that are known to be expressed, while up to 44 appear to be specifically expressed in barley. CONCLUSIONS: Our study, the first large scale investigation of small RNAs in barley, has identified up to 100 miRNAs. We demonstrate that reliable identification of miRNAs via deep sequencing in a species whose genome has not been sequenced requires a more careful analysis of sequencing errors than is commonly performed. We devised a read filtering procedure for dealing with errors. In addition, we found that the use of a large dataset of almost 35 million reads permits the use of read abundance distributions along putative precursor sequences as a practical tool for isolating miRNAs in a large background of reads originating from other non-coding and coding RNAs. This study therefore provides a generic approach for discovering novel miRNAs where no genome sequence is available.
Project description:Barley is one of the founder crops of Old world agriculture and has become the fourth most important cereal worldwide. Information on genome-scale DNA polymorphisms allows elucidating the evolutionary history behind domestication, as well as discovering and isolating useful genes for molecular breeding. Deep transcriptome sequencing enables the exploration of sequence variations in transcribed sequences; such analysis is particularly useful for species with large and complex genomes, such as barley. In this study, we performed RNA sequencing of 20 barley accessions, comprising representatives of several biogeographic regions and a wild ancestor. We identified 38,729 to 79,949 SNPs in the 19 domesticated accessions and 55,403 SNPs in the wild barley and revealed their genome-wide distribution using a reference genome. Genome-scale comparisons among accessions showed a clear differentiation between oriental and occidental barley populations. The results based on population structure analyses provide genome-scale properties of sub-populations grouped to oriental, occidental and marginal groups in barley. Our findings suggest that the oriental population of domesticated barley has genomic variations distinct from those in occidental groups, which might have contributed to barley's domestication.
Project description:Eight tissues of cultivar Morex (three biological replications each) earmarking stages of the barley life cycle from germinating grain to maturing caryopsis were selected for deep RNA sequencing (RNA-seq)
Project description:Cas endonuclease-mediated genome editing provides a long-awaited molecular biological approach to the modification of predefined genomic target sequences in living organisms. Although <i>cas9</i>/guide (g)RNA constructs are straightforward to assemble and can be customized to target virtually any site in the plant genome, the implementation of this technology can be cumbersome, especially in species like triticale that are difficult to transform, for which only limited genome information is available and/or which carry comparatively large genomes. To cope with these challenges, we have pre-validated <i>cas9</i>/gRNA constructs (1) by frameshift restitution of a reporter gene co-introduced by ballistic DNA transfer to barley epidermis cells, and (2) via transfection in triticale protoplasts followed by either a T7E1-based cleavage assay or by deep-sequencing of target-specific PCR amplicons. For exemplification, we addressed the triticale <i>ABA 8'-hydroxylase 1</i> gene, one of the putative determinants of pre-harvest sprouting of grains. We further show that in-del induction frequency in triticalecan beincreased by TREX2 nuclease activity, which holds true for both well- and poorly performing gRNAs. The presented results constitute a sound basis for the targeted induction of heritable modifications in triticale genes.