Expression data from longissimus dorsi of backcross Iberian x Landrace individuals
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ABSTRACT:
ORGANISM(S): Sus scrofa
SUBMITTER: Ana Fernandez
PROVIDER: E-GEOD-52626 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The integration of the results of QTL fine-mapping with microarray expression data offers a promising tool for understanding the genetic mechanisms influencing complex traits as fatty acid composition in pigs. The expression level of each probe may be treated as a quantitative trait and the marker genotypes used to map loci with regulatory effect on the gene expression level (eQTL) According to our previous linkage results, we carry out an eQTL scan focused on chromosomal regions showing tissue-consistent effects on fatty acids with Longissimus dorsi gene expression data in order to detect potentional candidate genes underlying the QTL previously detected.
2013-11-22 | GSE52626 | GEO
Project description:In the last 20 years, there has been significant research towards defining the genetic basis of lipid metabolism and meat quality related traits in pigs. Nowadays, the study of the transcriptome and its regulatory mechanisms allows going far beyond in the genetic dissection of these complex traits. In present study, a genome-wide eQTL scan aiming to detect pig genome regions regulating levels of skeletal muscle mRNA expression has been performed. This study has been conducted on a commercial Duroc population where a number of QTL for muscle fat deposition and fatty acid composition had been detected. GeneChip Porcine Genome® arrays (Affymetrix) were used to determine the gene expression levels of gluteus medius samples from 105 Duroc pigs belonging to two groups with divergent phenotypes for fatness traits. This experimental design aimed to favour detection of eQTL affecting genes related to lipid metabolism and meat quality traits. The whole genome scan with a panel of 110 microsatellites allowed us detecting 613 genome-wide significant eQTL unequally distributed across the pig genome, SSC5 and SSC3 harbouring the highest number of eQTL. Moreover, 11 genome regions with eQTL affecting the expression levels of a high number of genes (eQTL hot spots) have been described. After mapping target probes and discarding low quality probes, a total of 59 cis- and 396 trans-acting eQTL were retained for further analyses. The functional classification showed that lipid-related GO terms were not the most enriched by the list of eQTL-regulated genes. However, a number of regulated genes functionally related to lipid metabolism and fat deposition traits were identified, and their functional relationship with these phenotypes were further investigated. With this purpose, eQTL results were integrated with 1) QTL linkage maps and 2) correlation data between phenotypes and gene expression levels. As a result, a comprehensive list of 29 positional and functional candidate genes was elaborated. These results represent a valuable contribution to the comprehension of genetic regulation of skeletal muscle individual gene expression in swine species, and a first step towards disentangling gene networks and molecular mechanisms involved in lipid metabolism and meat quality traits. 105 gluteus medius samples from 105 animals belonging to two groups of 53 and 52 animals each: HIGH group had higher carcass, plasma and muscle fat content; LOW group had lower carcass, plasma and muscle fat content
2010-12-16 | E-GEOD-26091 | biostudies-arrayexpress
Project description:In the last 20 years, there has been significant research towards defining the genetic basis of lipid metabolism and meat quality related traits in pigs. Nowadays, the study of the transcriptome and its regulatory mechanisms allows going far beyond in the genetic dissection of these complex traits. In present study, a genome-wide eQTL scan aiming to detect pig genome regions regulating levels of skeletal muscle mRNA expression has been performed. This study has been conducted on a commercial Duroc population where a number of QTL for muscle fat deposition and fatty acid composition had been detected. GeneChip Porcine Genome® arrays (Affymetrix) were used to determine the gene expression levels of gluteus medius samples from 105 Duroc pigs belonging to two groups with divergent phenotypes for fatness traits. This experimental design aimed to favour detection of eQTL affecting genes related to lipid metabolism and meat quality traits. The whole genome scan with a panel of 110 microsatellites allowed us detecting 613 genome-wide significant eQTL unequally distributed across the pig genome, SSC5 and SSC3 harbouring the highest number of eQTL. Moreover, 11 genome regions with eQTL affecting the expression levels of a high number of genes (eQTL hot spots) have been described. After mapping target probes and discarding low quality probes, a total of 59 cis- and 396 trans-acting eQTL were retained for further analyses. The functional classification showed that lipid-related GO terms were not the most enriched by the list of eQTL-regulated genes. However, a number of regulated genes functionally related to lipid metabolism and fat deposition traits were identified, and their functional relationship with these phenotypes were further investigated. With this purpose, eQTL results were integrated with 1) QTL linkage maps and 2) correlation data between phenotypes and gene expression levels. As a result, a comprehensive list of 29 positional and functional candidate genes was elaborated. These results represent a valuable contribution to the comprehension of genetic regulation of skeletal muscle individual gene expression in swine species, and a first step towards disentangling gene networks and molecular mechanisms involved in lipid metabolism and meat quality traits.
2010-12-16 | GSE26091 | GEO
Project description:We used microarrays and a previously established linkage map to localize the genetic determinants of brain gene expression for a backcross family of lake whitefish species pairs (Coregonus sp.). Our goals were to elucidate the genomic distribution and sex-specificity of brain expression QTL (eQTL) and to determine the extent to which genes controlling transcriptional variation may underlie adaptive divergence in the recently evolved dwarf (limnetic) and normal (benthic) whitefish. We observed a sex-bias in transcriptional genetic architecture, with more eQTL observed in males, as well as divergence in genome location of eQTL between sexes. Hotspots of nonrandom aggregations of up to 32 eQTL in one location were observed. We identified candidate genes for species pair divergence involved with energetic metabolism, protein synthesis, and neural development based on co-localization of eQTL for these genes with eight previously identified adaptive phenotypic QTL and four previously identified outlier loci from a genome scan in natural populations. 88% of eQTL-phenotypic QTL co-localization involved growth rate and condition factor QTL, two traits central to adaptive divergence between whitefish species pairs. Hotspots co-localized with phenotypic QTL in several cases, revealing possible locations where master regulatory genes, such as a zinc finger protein in one case, control gene expression directly related to adaptive phenotypic divergence. We observed little evidence of co-localization of brain eQTL with behavioral QTL, which provides insight on the genes identified by behavioral QTL studies. These results extend to the transcriptome level previous work illustrating that selection has shaped recent parallel divergence between dwarf and normal lake whitefish species pairs and that metabolic, more than morphological differences appear to play a key role in this divergence. Keywords: eQTL mapping, gene expression, linkage mapping, adaptive radiation, Coregonus, microarrays
2008-09-01 | GSE12068 | GEO
Project description:The experiment aimed at studying gene expression differences in longissimus dorsi muscle from pigs from two groups: High versus low intramuscular fat (IMF). The animals were selected from a crossbred population of Landrace x Yorkshire/Landrace x Duroc animals, where we have previously found a highly significant QTL for IMF (Grindflek et al. 2001: "Detection of quantitative trait loci for meat quality in a commercial slaughter pig cross", Mammalian Genome 12(4): 299-304), and by microarray analysis we hoped to identify candidate genes for the QTL and/or pathways that are affected by the genes responsible for the QTL. Keywords: phenotype comparison
2013-01-01 | GSE12927 | GEO
Project description:A QTL analysis between inbred mouse strains MRL/MpJ and SM/J was performed to identify genetic loci influencing high-density lipoprotein (HDL) cholesterol and triglycerides (TG) at eight weeks of age in F2 mice fed a chow diet. In order to narrow down lists of candidate genes, expression levels from liver tissue were used to test for differential expression among parental and F1 strains and to scan for eQTL in F2 animals. We provide evidence for Mppe1 (Chr 18) as an HDL QTL candidate gene and Cyp2d26 (Chr 15) as a TG QTL candidate gene.
2011-11-28 | GSE25322 | GEO
Project description:The experiment aimed at studying gene expression differences in longissimus dorsi muscle from pigs from two groups: High versus low intramuscular fat (IMF). The animals were selected from a crossbred population of Landrace x Yorkshire/Landrace x Duroc animals, where we have previously found a highly significant QTL for IMF (Grindflek et al. 2001: "Detection of quantitative trait loci for meat quality in a commercial slaughter pig cross", Mammalian Genome 12(4): 299-304), and by microarray analysis we hoped to identify candidate genes for the QTL and/or pathways that are affected by the genes responsible for the QTL. Keywords: phenotype comparison Direct dye-swap design, with 14 animals in each group (high IMF and low IMF) on 14 separate arrays
2013-01-01 | E-GEOD-12927 | biostudies-arrayexpress
Project description:We used microarrays and a previously established linkage map to localize the genetic determinants of brain gene expression for a backcross family of lake whitefish species pairs (Coregonus sp.). Our goals were to elucidate the genomic distribution and sex-specificity of brain expression QTL (eQTL) and to determine the extent to which genes controlling transcriptional variation may underlie adaptive divergence in the recently evolved dwarf (limnetic) and normal (benthic) whitefish. We observed a sex-bias in transcriptional genetic architecture, with more eQTL observed in males, as well as divergence in genome location of eQTL between sexes. Hotspots of nonrandom aggregations of up to 32 eQTL in one location were observed. We identified candidate genes for species pair divergence involved with energetic metabolism, protein synthesis, and neural development based on co-localization of eQTL for these genes with eight previously identified adaptive phenotypic QTL and four previously identified outlier loci from a genome scan in natural populations. 88% of eQTL-phenotypic QTL co-localization involved growth rate and condition factor QTL, two traits central to adaptive divergence between whitefish species pairs. Hotspots co-localized with phenotypic QTL in several cases, revealing possible locations where master regulatory genes, such as a zinc finger protein in one case, control gene expression directly related to adaptive phenotypic divergence. We observed little evidence of co-localization of brain eQTL with behavioral QTL, which provides insight on the genes identified by behavioral QTL studies. These results extend to the transcriptome level previous work illustrating that selection has shaped recent parallel divergence between dwarf and normal lake whitefish species pairs and that metabolic, more than morphological differences appear to play a key role in this divergence. Keywords: eQTL mapping, gene expression, linkage mapping, adaptive radiation, Coregonus, microarrays The objective of this study was to elucidate the genomic distribution and sex-specificity of brain eQTL in dwarf and normal lake whitefish. Dissected brain tissue (250-350 mg) was sampled for 55 individuals from a hybrid x dwarf backcross mapping family. We used a loop design (YANG and SPEED 2002; CHURCHILL 2002) to maximize the number of sampled meioses. Each of 55 samples was technically replicated on two distinct slides, while performing dye swapping (Cy3 and Alexa) to estimate the dye intensity variation bias. After correcting for local background, raw intensity values were both log2 transformed and normalized using the regional LOWESS method implemented in the R/MANOVA software (KERR et al. 2000). We used a previously generated linkage map based on the same backcross individuals for which gene expression was measured. eQTL mapping was performed with QTL Cartographer.
2008-09-01 | E-GEOD-12068 | biostudies-arrayexpress
Project description:We studied the influence of genetic type (pure Iberian pigs vs crossbred with Duroc) on l.dorsi transcriptome Background: The two main genetic types in Iberian pig production show important phenotypic differences in growth, fattening and tissue composition since early developmental stages. The objective of this work was the evaluation of muscle transcriptome profile in young animals of both genetic types, in order to identify genes, pathways and transcription factors responsible of their phenotypic differences. Contemporary families coming from pure Iberian pigs (IB) or from crossing with Duroc boars (DUxIB) were generated. Piglets (14 from each genetic type) were sacrificed at weaning (28 days) and longissimus dorsi muscle was sampled for composition and gene expression studies. RNA was obtained and hybridized to Affymetrix Porcine Genechip expression arrays. Results: Loin muscle composition showed significant differences between genetic types in intramuscular fat content (6% vs. 4.2% in IB and DUxIB animals, respectively, P=0.009) and in saturated and monounsaturated fatty acid contents (P=0.019 and P=0.044, respectively). Statistical analysis of gene expression data allowed the identification of 256 differentially expressed (DE) genes between genetic types (FDR<0.10), 102 upregulated in IB and 154 upregulated in DUxIB. The size of the effects ranged between 1.2x and 7.8x. Transcript differences were validated for a subset of DE genes by qPCR. Some candidate genes with known effects on muscle growth were found among the DE genes upregulated in DUxIB (IGF2, collagens, integrins). Genes related to lipid metabolism and proteolysis were found among the genes upregulated in IB (ME1, ELOVL6, caspases, catepsins, ubiquitination proteins). We observed alteration in biological functions related to extracellular matrix organization, cellular adhesion, muscle growth and lipid metabolism. Transcription factors (TF) potentially involved in the expression differences found were identified by calculating the regulatory impact factors (RIF). Sixteen TF were found, some of them with known relationship with muscle development (MSTN, SIX4), adipogenesis (CEBPD, PPARGC1B), or extracellular matrix processes (MAX, MXI1). Correlation among the expression of these TF and DE genes show relevant differences between genetic types. Conclusion: The results contribute valuable information about molecular mechanisms determining the phenotypic differences of growth and meat quality between the genetic types studied, mainly related to the development and function of the extracellular matrix and also to some metabolic processes as proteolysis and lipid metabolism. 28 male piglets were employed. 14 animals coming for pure Iberian parents and 14 coming from the crossing of Duroc boars with Iberian sows. Animals were sacrificed at 28 d of age. At the sacrifice, longissimus dorsi muscle tissue was sampled from each animal.
2014-06-11 | E-GEOD-53029 | biostudies-arrayexpress
Project description:Previous results from a genome scan in a F2 Iberian by Meishan intercross showed several chromosome regions associated with litter size traits. In order to identify candidate genes underlying these QTL we have performed an ovary gene expression analysis during pregnancy. F2 sows were ranked by their estimated breeding values for prolificacy, the six sows with higher EBV (HIGH prolificacy) and the six with lower EBV (LOW prolificacy) were selected. Samples were hybridized to Affymetrix porcine expression microarrays. The statistical analysis with a mixed-model approach identified 221 differentially expressed probes, representing 189 genes. These genes were functionally annotated in order to identify the genetic pathways overrepresented. Among the most represented functional groups the first one was immune system response activation against external stimulus. The second group was made up of genes which regulate the maternal homeostasis by complement and coagulation cascades. The last group was involved on lipid and fatty acid enzymes of metabolic processes, which participate in steroidogenesis pathway. In order to identify powerful candidate genes for prolificacy, the second approach of this study was merging microarray data with position information of QTL affecting litter size, previously detected in the same experimental cross. According to this, we have identified 27 differentially expressed genes co-localized with QTL for litter size traits, which fulfill the biological, positional and functional criteria. Twelve ovary samples: six high prolific sows and low prolific sows, slaughtered after 30 days of pregnancy. Each sample is the average between right and left ovary from each sow.
2010-05-07 | E-GEOD-21383 | biostudies-arrayexpress