Project description:In this study, two accessions of Arabidopsis thaliana (Columbia and Landsberg erecta) were crossed and tetrads were obtained using thanks to the the quartet mutation, which keeps the 4 haploid pollen grains from a single meiosis attached together. By fertilising a plant (of ecotype Columbia) with a single tetrad, then selecting seeds from siliques containing exactly four seeds and finally sequencing the 4 developed plants, we can access the complete history of meiotic recombination events occurring in a single male meiosis. Comparison of the genomic sequences (WGS) of the 4 plants in a tetrad makes it possible to identify meiotic COs and NCOS events in each tetrad thanks to the numerous polymorphisms specific to each of the parental genomes. The analysis of the WGS tetrads data consists of genotyping a series of SNV markers (differentiating Columbia and Landsberg) positioned on the five chromosomes for the 4 (M1, M2, M3, M4) individuals of a tetrad, representing the 4 chromatids of each chromosomes. A total of 20 tetrads, the F1 and the two parental accessions Columbia and Landsberg erecta were sequenced.
Project description:A major effort is underway to study the natural variation within the model plant species, Arabidopsis thaliana. Much of this effort is focused on genome resequencing, however the translation of genotype to phenotype will be largely effected through variations within the transcriptomes at the sequence and expression levels. To examine the cross-talk between natural variation in genomes and transcriptomes, we have examined the transcriptomes of three divergent A. thaliana accessions using tiling arrays. Combined with genome resequencing efforts, we were able to adjust the tiling array datasets to account for polymorphisms between the accessions and therefore gain a more accurate comparison of the transcriptomes. The corrected results for the transcriptomes allowed us to correlate higher gene polymorphism with greater variation in transcript level among the accessions. Our results demonstrate the utility of combining genomic data with tiling arrays to assay non-reference accession transcriptomes.
Project description:A major effort is underway to study the natural variation within the model plant species, Arabidopsis thaliana. Much of this effort is focused on genome resequencing, however the translation of genotype to phenotype will be largely effected through variations within the transcriptomes at the sequence and expression levels. To examine the cross-talk between natural variation in genomes and transcriptomes, we have examined the transcriptomes of three divergent A. thaliana accessions using tiling arrays. Combined with genome resequencing efforts, we were able to adjust the tiling array datasets to account for polymorphisms between the accessions and therefore gain a more accurate comparison of the transcriptomes. The corrected results for the transcriptomes allowed us to correlate higher gene polymorphism with greater variation in transcript level among the accessions. Our results demonstrate the utility of combining genomic data with tiling arrays to assay non-reference accession transcriptomes.
Project description:Low temperature is one of the major abiotic stresses limiting rice growth and productivity, it is urgent to reveal the genetic and molecular mechanisms of plant responses to low temperature stress and to search for useful genetic resources for improving low-temperature tolerance. the 8 accessions from China Core Collection include 4 cold tolerance accessions, 3 sensitivity accessions and 1 intermediate type accession. We used microarrays to detail variation of the gene expression after cold treatment and screen more cold-response genes in rice.
Project description:Genetic diversity in plants is remarkably high. Recent whole genome sequencing (WGS) of 67 rice accessions recovered 10,872 novel genes. Comparison of the genetic architecture among divergent populations or between crops and wild relatives is essential for obtaining functional components determining crucial traits. However, many major crops have gigabase-scale genomes, which are not well-suited to WGS. Existing cost-effective sequencing approaches including re-sequencing, exome-sequencing and restriction enzyme-based methods all have difficulty in obtaining long novel genomic sequences from highly divergent population with large genome size. The present study presented a reference-independent core genome targeted sequencing approach, CGT-seq, which employed epigenomic information from both active and repressive epigenetic marks to guide the assembly of the core genome mainly composed of promoter and intragenic regions. This method was relatively easily implemented, and displayed high accuracy, sensitivity and specificity for capturing the core genome of bread wheat. 95% intragenic and 89% promoter region from wheat were covered by CGT-seq read. We further demonstrated in rice that CGT-seq captured hundreds of novel genes and regulatory sequences from a previously unsequenced ecotype. Together, with specific enrichment and sequencing of regions within and nearby genes, CGT-seq is a time- and resource-effective approach to profiling functionally relevant regions in sequenced and non-sequenced populations with large genomes.
Project description:A major effort is underway to study the natural variation within the model plant species, Arabidopsis thaliana. Much of this effort is focused on genome resequencing, however the translation of genotype to phenotype will be largely effected through variations within the transcriptomes at the sequence and expression levels. To examine the cross-talk between natural variation in genomes and transcriptomes, we have examined the transcriptomes of three divergent A. thaliana accessions using tiling arrays. Combined with genome resequencing efforts, we were able to adjust the tiling array datasets to account for polymorphisms between the accessions and therefore gain a more accurate comparison of the transcriptomes. The corrected results for the transcriptomes allowed us to correlate higher gene polymorphism with greater variation in transcript level among the accessions. Our results demonstrate the utility of combining genomic data with tiling arrays to assay non-reference accession transcriptomes. Wild type accessions Col-0, Bur-0 and C24 were grown on soil at 23M-BM-0C with a 16 hour light period. Inflorescence tissue up to floral stage 14 was used for RNA extraction. Samples were collected 7-8 hours into the light period, with tissue from five plants pooled for each sample. RNA samples were converted into double stranded and hybridized to whole genome tiling arrays (Affymetrix Arabidopis Tiling1.0RM-BM-.). Three biological replicates were performed for each accession.
Project description:A major effort is underway to study the natural variation within the model plant species, Arabidopsis thaliana. Much of this effort is focused on genome resequencing, however the translation of genotype to phenotype will be largely effected through variations within the transcriptomes at the sequence and expression levels. To examine the cross-talk between natural variation in genomes and transcriptomes, we have examined the transcriptomes of three divergent A. thaliana accessions using tiling arrays. Combined with genome resequencing efforts, we were able to adjust the tiling array datasets to account for polymorphisms between the accessions and therefore gain a more accurate comparison of the transcriptomes. The corrected results for the transcriptomes allowed us to correlate higher gene polymorphism with greater variation in transcript level among the accessions. Our results demonstrate the utility of combining genomic data with tiling arrays to assay non-reference accession transcriptomes. Wild type accessions Col-0 were grown on soil at 16M-BM-0C with a 16 hour light period. Inflorescence tissue up to floral stage 14 was used for RNA extraction. Samples were collected 7-8 hours into the light period, with tissue from five plants pooled for each sample. RNA samples were converted into double stranded and hybridized to whole genome tiling arrays (Affymetrix Arabidopis Tiling1.0RM-BM-.). Three biological replicates were performed for each accession.