Project description:Quantitative trait loci mapping and transcriptome analysis reveal candidate genes regulating the response to ozone in Arabidopsis thaliana
Project description:Many Arabidopsis thaliana accession show sensitvity to the air pollutant ozone, including the accession Cvi-0 from the Cape Verde Islands. To understand and assist in genetic mapping of loci causing the ozone sensitvity of Cvi-0, transcript profiling was performed in Cvi-0, the tolerant Col-0, and a near isogenic line (Col-S) where ozone sensitivity was introgressesed from Cvi-0 to Col-0 through eight rounds of backcrossing.
Project description:To assess natural variation in gene expression in Arabidopsis thaliana, genome wide gene expression variation was analyzed in a Ler/Cvi recombinant inbred line (RIL) population.The variation in expression could be explained for many genes by expression quantitative trait loci (eQTLs). These eQTLs are combined with regulator candidate gene selection to generate genetic regulatory networks.
Project description:The formation of Reactive oxygen species (ROS) has been detected in all cellular departments and even in apoplastic space of plants. As multifaceted molecule, ROS are known to accumulate in response to various stresses, and ROS burst accompanied with transcriptomic reprogramming leading to defense response or programmed cell death. Acute ozone exposure has been used as a noninvasive tool to study ROS burst induced defense response and cell death for a long time. Moreover the variation of ozone sensitivity in different Arabidopsis accessions highlights the flexibility of complex genetic architecture to adapt to specific stresses. In this study, we combine classic Quantitative Trait Loci (QTL) mapping and RNA-seq to identify the cause QTLs and potential gene candidates in response to ozone. RNA sequencing was performed on both control and ozone treated 3 weeks old accessions C24 (ozone tolerant), Te (ozone sensitive) and on a RIL line CT101 (a hypersensitive line of RIL population from reciprocal cross between C24 and Te), in triplicate. We identified 69 potential genes candidates inside the QTL regions and about 200 potential genes outside QTL region in response to ozone by comparing control to treatment within same genotype or comparing control between genotypes. Transcriptome profiling of ozone response using two arabidopsis accessions C24 and Te with different ozone sensitivity
Project description:The formation of Reactive oxygen species (ROS) has been detected in all cellular departments and even in apoplastic space of plants. As multifaceted molecule, ROS are known to accumulate in response to various stresses, and ROS burst accompanied with transcriptomic reprogramming leading to defense response or programmed cell death. Acute ozone exposure has been used as a noninvasive tool to study ROS burst induced defense response and cell death for a long time. Moreover the variation of ozone sensitivity in different Arabidopsis accessions highlights the flexibility of complex genetic architecture to adapt to specific stresses. In this study, we combine classic Quantitative Trait Loci (QTL) mapping and RNA-seq to identify the cause QTLs and potential gene candidates in response to ozone. RNA sequencing was performed on both control and ozone treated 3 weeks old accessions C24 (ozone tolerant), Te (ozone sensitive) and on a RIL line CT101 (a hypersensitive line of RIL population from reciprocal cross between C24 and Te), in triplicate. We identified 69 potential genes candidates inside the QTL regions and about 200 potential genes outside QTL region in response to ozone by comparing control to treatment within same genotype or comparing control between genotypes.
Project description:Expression level polymorphisms (ELPs) often result in cis-acting expression quantitative trait loci (cis-eQTL), which are important QTL and association mapping tools and account significantly for phenotypic variability. Generally, it is assumed that such stably heritable ELP represent regulatory element polymorphisms in the respective genes. However, comprehensive genome-wide analyses linking expression level, regulatory sequence and gene structure variation are missing, preventing definite verification of this assumption. Here we analyzed heritability of ELP observed between Arabidopsis thaliana accessions Eil-0 and Lc-0 by comparing genotyped recombinant inbred lines (RIL) to their parents in microarray analyses. Keywords: expression level polymorphism, Arabidopsis thaliana accessions, recombinant inbred lines
Project description:Expression level polymorphisms (ELPs) often result in cis-acting expression quantitative trait loci (cis-eQTL), which are important QTL and association mapping tools and account significantly for phenotypic variability. Generally, it is assumed that such stably heritable ELP represent regulatory element polymorphisms in the respective genes. However, comprehensive genome-wide analyses linking expression level, regulatory sequence and gene structure variation are missing, preventing definite verification of this assumption. Here we analyzed heritability of ELP observed between Arabidopsis thaliana accessions Eil-0 and Lc-0 by comparing genotyped recombinant inbred lines (RIL) to their parents in microarray analyses. Keywords: expression level polymorphism, Arabidopsis thaliana accessions, recombinant inbred lines In order to analyze expression level polymorphisms between the accessions Eil-0 and Lc-0, three independently grown seedling pools were analyzed by two color co-hybridization of the labeled cDNAs in dyeswap experiments, giving a total of six slides. For the analysis of gene expression in seedlings of 7 different RILs, each RIL sample was co-hybridized with each parent (Eil-0 and Lc-0) in a dyeswap, resulting in two slides per parent vs. RIL comparison. The total number of slides in this study was 34.
Project description:To assess plasticity in genetic regulation of gene expression in Arabidopsis thaliana, genome wide gene expression variation was analyzed in a Ler/Cvi recombinant inbred line (RIL) population treated with low-light. The variation in expression could be explained for many genes by expression quantitative trait loci (eQTLs), which were compared to a previous genetical genomics study in the same untreated population. Please note Characteristics[StrainOrLine] is the population of 162 recombinant inbred lines between the accessions Ler x Cvi. Ler and Cvi are the names of the parental accessions.
Project description:rice flag leaves at heading stage from three chromosome substitution line populations, which were respectively constructed by introducing genomic segments from japonica cultivar Niponbare, indica cultivar Minghui 63 and wild accession ACC10, to an indica cultivar Zhenshan 97, were collected. Metabolomics profile was conducted to generate quantitative trait loci that may affect contents of metabolites, and candidate genes were assigned.
Project description:Coordinated regulation of gene expression levels across a series of experimental conditions provides valuable information about the functions of correlated transcripts. To map gene regulatory pathways, we used microarray-derived gene expression measurements in 60 individuals of an F2 sample segregating for diabetes. We performed correlation analysis among ~40,000 expression traits. By combining correlation among expression traits and linkage mapping information, we were able to identify regulatory networks, make functional predictions to uncharacterized genes, and characterize novel members of known pathways. Using 36 seed traits, we found evidence of coordinate regulation of 160 G-protein coupled receptor (GPCR) pathway expression traits. Of the 160 traits, 50 had their major LOD peak within 8 cM of a locus on chromosome 2, and 81 others had a secondary peak in this region. A previously uncharacterized Riken cDNA clone, which showed strong correlation with stearoyl CoA desaturase 1 expression, was experimentally validated to be responsive to conditions that regulate lipid metabolism. Using linkage mapping, we identified multiple genes whose expression is under the control of transcription regulatory loci. Trait-correlation combined with linkage mapping can reveal regulatory networks that would otherwise be missed if we only studied mRNA traits with statistically significant linkages in this small cross. The combined analysis is more sensitive compared with linkage mapping only. References: Kendziorski C., M. Chen, M. Yuan, H. Lan, and A.D. Attie. Statistical Methods for Expression Quantitative Trait Loci (eQTL) Mapping. Biometrics, to appear, 2005. Lan H, Chen M, Flowers JB, Yandell BS, Stapleton DS, et al. (2006) Combined Expression Trait Correlations and Expression Quantitative Trait Locus Mapping. PLoS Genet 2(1): e6. Keywords: Genetics of gene expression