Genome-wide expression quantitative trait loci (eQTL) analysis in maize
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ABSTRACT:
ORGANISM(S): Zea mays
PROVIDER: GSE29964 | GEO | 2011/06/22
SECONDARY ACCESSION(S): PRJNA140841
REPOSITORIES: GEO
Similar Datasets
Project description:Background: Expression QTL analyses have shed light on transcriptional regulation in numerous species of plants, animals, and yeasts. These microarray-based analyses identify regulators of gene expression as either cis-acting factors that regulate proximal genes, or trans-acting factors that function through a variety of mechanisms to affect transcript abundance of unlinked genes. Results: A hydroponics-based genetical genomics study in roots of a Zea mays IBM2 Syn10 double haploid population identified tens of thousands of cis-acting and trans-acting eQTL. Cases of false-positive eQTL, which results from the lack of complete genomic sequences from both parental genomes, were described. A candidate gene for a trans-acting regulatory factor was identified through positional cloning. The unexpected regulatory function of a class I glutamine amidotransferase controls the expression of an ABA 8’-hydroxylase pseudogene. For each of two biological replicates, tissue was collected from B73 and Mo17 parental controls and the IBM2 Syn10 doubled haploid mapping population at 4 weeks after germination (V5 stage). One hundred thirty-five IBM2 Syn10 lines were used in this study. The tissue sampled was the 1.5 cm tip of all crown roots that had developed at the time of harvest, representing the most metabolically active region based on whole-tissue visualization of triphenyl tetrazolium chloride staining. Tissues were flash frozen in liquid nitrogen and stored at -80º C. They were manually ground into a fine powder using a mortar and pestle on dry ice. Two-channel hybridizations were considered as single channel. Therefore, the same raw data file is linked to two Samples appended as _Cy3 and _Cy5.
2011-06-22 | E-GEOD-29964 | biostudies-arrayexpress
Project description:A genome-wide eQTL analysis was performed in whole blood samples collected from 76 Japanese subjects. RNA microarray analysis was performed for 3 independent samples that were genotyped in a genome-wide scan. The correlations between the genotypes of 534,404 autosomal single nucleotide polymorphisms (SNPs) and the expression levels of 30,465 probes were examined for each sample. The SNP-probe pairs with combined correlation coefficients of all 3 samples corresponding to P < 3.10 × 10-12 (i.e., Bonferroni-corrected P < 0.05) were considered significant. SNP-probe pairs with a high likelihood of cross-hybridization and SNP-in-probe effects were excluded to exclude false positive results. We identified 102 cis-acting and 5 trans-acting eQTL regions. The cis-eQTL regions were widely distributed both upstream and downstream of the gene, as well as within the gene.
2012-11-27 | GSE42487 | GEO
Project description:A genome-wide eQTL analysis was performed in whole blood samples collected from 76 Japanese subjects. RNA microarray analysis was performed for 3 independent samples that were genotyped in a genome-wide scan. The correlations between the genotypes of 534,404 autosomal single nucleotide polymorphisms (SNPs) and the expression levels of 30,465 probes were examined for each sample. The SNP-probe pairs with combined correlation coefficients of all 3 samples corresponding to P < 3.10 × 10-12 (i.e., Bonferroni-corrected P < 0.05) were considered significant. SNP-probe pairs with a high likelihood of cross-hybridization and SNP-in-probe effects were excluded to exclude false positive results. We identified 102 cis-acting and 5 trans-acting eQTL regions. The cis-eQTL regions were widely distributed both upstream and downstream of the gene, as well as within the gene.
2012-11-27 | GSE42229 | GEO
Project description:A genome-wide eQTL analysis was performed in whole blood samples collected from 76 Japanese subjects. RNA microarray analysis was performed for 3 independent samples that were genotyped in a genome-wide scan. The correlations between the genotypes of 534,404 autosomal single nucleotide polymorphisms (SNPs) and the expression levels of 30,465 probes were examined for each sample. The SNP-probe pairs with combined correlation coefficients of all 3 samples corresponding to P < 3.10 × 10-12 (i.e., Bonferroni-corrected P < 0.05) were considered significant. SNP-probe pairs with a high likelihood of cross-hybridization and SNP-in-probe effects were excluded to exclude false positive results. We identified 102 cis-acting and 5 trans-acting eQTL regions. The cis-eQTL regions were widely distributed both upstream and downstream of the gene, as well as within the gene.
2012-11-27 | GSE42228 | GEO
Project description:A genome-wide eQTL analysis was performed in whole blood samples collected from 76 Japanese subjects. RNA microarray analysis was performed for 3 independent samples that were genotyped in a genome-wide scan. The correlations between the genotypes of 534,404 autosomal single nucleotide polymorphisms (SNPs) and the expression levels of 30,465 probes were examined for each sample. The SNP-probe pairs with combined correlation coefficients of all 3 samples corresponding to P < 3.10 × 10-12 (i.e., Bonferroni-corrected P < 0.05) were considered significant. SNP-probe pairs with a high likelihood of cross-hybridization and SNP-in-probe effects were excluded to exclude false positive results. We identified 102 cis-acting and 5 trans-acting eQTL regions. The cis-eQTL regions were widely distributed both upstream and downstream of the gene, as well as within the gene.
2012-11-27 | GSE42227 | GEO
Project description:We performed expression quantitative trait locus (eQTL) mapping between two strains of Tetranychus urticae (the two-spotted spider mite), a generalist herbivore known for its rapid evolution of acaricide resistance. For parents, we used the inbred strain MR-VPi that is highly resistant to multiple acaricides in different classes, and the inbred strain ROS-ITi that is comparatively susceptible to many acaricides. The eQTL mapping experiment was performed with F3 samples, and thousands of trans and cis eQTL were identified, including for genes in families known (or suspected) to be involved in the metabolism of xenobiotics (plant produced secondary compounds and acaricides). One trans eQTL hotspot was identified that strongly impacted the expression of many detoxification genes in different gene families. Follow up studies using derived near isogenic lines validated the trans eQTL hotspot, and RNA interference (RNAi) knockdown of tandemly duplicated genes encoding products with homology to the ligand binding domains of nuclear hormone receptor 96 genes impacted many of the same detoxification genes controlled by the hotspot.
2023-07-14 | GSE221677 | GEO
Project description:The aim of this study was to identify eQTL in Brassica rapa grown under altered soil phosphorus (P) supply, to understand better the genetic architecture of P-use efficiency (PUE) in plants. Recombinant inbred lines (RILs) of the BraIRRI mapping population were grown at adequate and growth-limiting soil P. Variation in leaf gene expression was quantified using an Agilent Brassica 95k oligonucleotide array. Informative gene expression markers (GEMs) were used to map eQTL and PUE-related QTL. Gene expression was highly dependent on soil P supply. However, the altered expression of many genes, including known P-responsive genes, was highly heritable. Interval mapping using P supply as a covariate revealed 18,876 eQTL, representing 15,912 unique probes. Notable trans-eQTL hotspots occurred on chromosomes A06 and A01; these were enriched with protein modification and phosphorus metabolism-related (A06), as well as chloroplast and photosynthesis-related (A01) transcripts. Regulatory loci and genes associated with P-use efficiency identified through eQTL analysis are potential targets for further characterisation and may have potential for crop improvement. Availability of the annotated B. rapa genome sequence will facilitate their study, including the separation of cis- and trans- effects.
2011-06-29 | GSE27052 | GEO
Project description:In this study we use RNAseq to explore allele specific expression (ASE) in adipose tissue of male and female F1 mice, produced from reciprocal crosses of C57BL/6J and DBA/2J strains. Comparison of the identified cis-eQTLs, to local-eQTLs, that were obtained from adipose tissue expression in two previous population based studies in our laboratory, yields poor overlap between the two mapping approaches, while both local-eQTL studies show highly concordant results. Specifically, local-eQTL studies show ~60% overlap between themselves, while only 15-20% of local-eQTLs are identified as cis by ASE, and less than 50% of ASE genes are recovered in local-eQTL studies. Utilizing recently published ENCODE data, we also find that ASE genes show significant bias for SNPs prevalence in DNase I hypersensitive sites that is ASE direction specific. We suggest a new approach to analysis of allele specific expression that is more sensitive and accurate than the commonly used fisher or chi-square statistics. Our analysis indicates that technical differences between the cis and local-eQTL approaches, such as differences in genomic background or sex specificity, account for relatively small fraction of the discrepancy. Therefore, we suggest that the differences between two eQTL mapping approaches may facilitate sorting of SNP-eQTL interactions into true cis and trans, and that a considerable portion of local-eQTL may actually represent trans interactions.
2014-06-05 | GSE58239 | GEO
Project description:In this study we use RNAseq to explore allele specific expression (ASE) in adipose tissue of male and female F1 mice, produced from reciprocal crosses of C57BL/6J and DBA/2J strains. Comparison of the identified cis-eQTLs, to local-eQTLs, that were obtained from adipose tissue expression in two previous population based studies in our laboratory, yields poor overlap between the two mapping approaches, while both local-eQTL studies show highly concordant results. Specifically, local-eQTL studies show ~60% overlap between themselves, while only 15-20% of local-eQTLs are identified as cis by ASE, and less than 50% of ASE genes are recovered in local-eQTL studies. Utilizing recently published ENCODE data, we also find that ASE genes show significant bias for SNPs prevalence in DNase I hypersensitive sites that is ASE direction specific. We suggest a new approach to analysis of allele specific expression that is more sensitive and accurate than the commonly used fisher or chi-square statistics. Our analysis indicates that technical differences between the cis and local-eQTL approaches, such as differences in genomic background or sex specificity, account for relatively small fraction of the discrepancy. Therefore, we suggest that the differences between two eQTL mapping approaches may facilitate sorting of SNP-eQTL interactions into true cis and trans, and that a considerable portion of local-eQTL may actually represent trans interactions. 4 samples - male and female, BxD and DxB adipose of pooled RNA (3 animals per pool) were analyzed with high coverage RNAseq data.
2014-06-05 | E-GEOD-58239 | biostudies-arrayexpress
Project description:The aim of this study was to identify eQTL in Brassica rapa grown under altered soil phosphorus (P) supply, to understand better the genetic architecture of P-use efficiency (PUE) in plants. Recombinant inbred lines (RILs) of the BraIRRI mapping population were grown at adequate and growth-limiting soil P. Variation in leaf gene expression was quantified using an Agilent Brassica 95k oligonucleotide array. Informative gene expression markers (GEMs) were used to map eQTL and PUE-related QTL. Gene expression was highly dependent on soil P supply. However, the altered expression of many genes, including known P-responsive genes, was highly heritable. Interval mapping using P supply as a covariate revealed 18,876 eQTL, representing 15,912 unique probes. Notable trans-eQTL hotspots occurred on chromosomes A06 and A01; these were enriched with protein modification and phosphorus metabolism-related (A06), as well as chloroplast and photosynthesis-related (A01) transcripts. Regulatory loci and genes associated with P-use efficiency identified through eQTL analysis are potential targets for further characterisation and may have potential for crop improvement. Availability of the annotated B. rapa genome sequence will facilitate their study, including the separation of cis- and trans- effects. The experiment was designed to identify expression QTL associated with availability of phosphorus in Brassica rapa. Seventy-eight informative lines from the “BraIRRI” mapping population of Brassica rapa L. (2n = 2x = 10; A-genome) and the two parent lines (IMB211, female; R500, male) were selected for study. The establishment of the BraIRRI population is described by Iniguez-Luy et al. (2009). Plants were grown from seed in compost, under two [P]ext treatments of 9 mg L-1 (low) or 30 mg L-1 (optimal) Olsen extractable P. RNA was extracted from leaf samples from one experimental run (78 lines at low and optimal [P]ext, with one line duplicated i.e. 158 samples), and from leaf samples from the parent lines at low and optimal P in all three experimental runs (12 samples) using a modified TRIzol extraction method (Hammond et al., 2006).
2011-06-29 | E-GEOD-27052 | biostudies-arrayexpress