The combination of gene expression profiling with linkage analysis has become a powerful paradigm for mapping gene expression quantitative trait loci (eQTL). To date, most studies have searched for eQTL by analyzing gene expression traits one at a time. As thousands of expression traits are typically analyzed, this can reduce power because of the need to correct for the number of hypothesis tests performed. In addition, gene expression traits exhibit a complex correlation structure, which is ignored when analyzing traits individually. To address these issues, we applied two different multivariate dimension reduction techniques, the Singular Value Decomposition (SVD) and Independent Component Analysis (ICA) to gene expression traits derived from a cross between two strains of Saccharomyces cerevisiae. Both methods decompose the data into a set of meta-traits, which are linear combinations of all the expression traits. The meta-traits were enriched for several Gene Ontology categories including metabolic
Life history traits such as fecundity are important to evolution because they make up components of lifetime fitness. Due to their polygenic architectures, such traits are difficult to investigate with genetic mapping. Therefore, little is known about their molecular basis. One possible way toward finding the underlying genes is to map intermediary molecular phenotypes, such as gene expression traits. We set out to map candidate quantitative trait genes for egg fecundity in the chicken by combining quantitative trait locus mapping in an advanced intercross of wild by domestic chickens with expression quantitative trait locus mapping in the same birds. We measured individual egg fecundity in 232 intercross chickens in two consecutive trials, the second one aimed at measuring brooding. We found 12 loci for different aspects of egg fecundity. We then combined the genomic confidence intervals of these loci with expression quantitative trait loci from bone and hypothalamus in the same intercross. ...
TY - JOUR. T1 - A novel quantitative trait locus, qCL1, involved in semi-dwarfism derived from Japanese rice cultivar Nipponbare. AU - Hori, Kiyosumi. AU - Yamamoto, Toshio. AU - Ebana, Kaworu. AU - Takeuchi, Yoshinobu. AU - Yano, Masahiro. PY - 2009/10/5. Y1 - 2009/10/5. N2 - To identify quantitative trait loci (QTLs) associated with culm length in Japanese japonica rice varieties, we conducted QTL analyses using a set of reciprocal backcrossed inbred lines (BILs) from crosses between Nipponbare and Koshihikari. We detected five QTLs in the two BILs that are involved in the culm-length difference between Nipponbare and Koshihikari. A QTL located on the short arm of chromosome 1, qCL1, was commonly detected near the simple sequence repeat (SSR) marker RM8068 in both BILs in three growing seasons. The Nipponbare allele of qCL1 shortened from 1.9 to 3.0 cm of culm length. Substitution lines (SLs) of Koshihikari in which the QTL was replaced with the Nipponbare allele exhibited decreased lengths of ...
The observation that variants regulating gene expression (expression quantitative trait loci, eQTL) are at a high frequency among SNPs associated with complex traits has made the genome-wide characterization of gene expression an important tool in genetic mapping studies of such traits. As part of a study to identify genetic loci contributing to bipolar disorder and other quantitative traits in members of 26 pedigrees from Costa Rica and Colombia, we measured gene expression in lymphoblastoid cell lines derived from 786 pedigree members. The study design enabled us to comprehensively reconstruct the genetic regulatory network in these families, provide estimates of heritability, identify eQTL, evaluate missing heritability for the eQTL, and quantify the number of different alleles contributing to any given locus. In the eQTL analysis, we utilize a recently proposed hierarchical multiple testing strategy which controls error rates regarding the discovery of functional variants. Our results ...
The present invention is in the field of plant breeding and disease resistance. More specifically, the invention includes a method for breeding soybean plants containing quantitative trait loci that are associated with resistance to Asian Soybean Rust (ASR), a fungal disease associated with Phakopsora spp. The invention further includes germplasm and the use of germplasm containing quantitative trait loci (QTL) conferring disease resistance for introgression into elite germplasm in a breeding program for resistance to ASR.
Identifying the genes underlying genetically complex traits is of fundamental importance for medicine, agriculture, and evolutionary biology. However, the level of resolution offered by traditional quantitative trait locus (QTL) mapping is usually coarse. We analyze here a trait closely related to fitness, ovariole number. Our initial interspecific mapping between Drosophila sechellia (8 ovarioles/ovary) and D. simulans (15 ovarioles/ovary) identified a major QTL on chromosome 3 and a minor QTL on chromosome 2. To refine the position of the major QTL, we selected 1038 additional recombinants in the region of interest using flanking morphological markers (selective phenotyping). This effort generated approximately one recombination event per gene and increased the mapping resolution by approximately seven times. Our study thus shows that using visible markers to select for recombinants can efficiently increase the resolution of QTL mapping. We resolved the major QTL into two epistatic QTL, QTL3a ...
OBJECTIVES: In sib pair studies, quantitative trait loci (QTL) identification may be adversely affected by non-normality in the phenotypic distribution, particularly when subjects falling in the tails of the distribution bias the trait mean or varian
IN the mapping of quantitative trait loci (QTL) in an experimental cross, selective genotyping (in which only the individuals at the extremes of the phenotype distribution are genotyped) can provide nearly equivalent power to complete genotyping at a reduced cost (Lander and Botstein 1989; Darvasi and Soller 1992).. Interval mapping with selectively genotyped data is best performed with consideration of all individuals, even those that were not genotyped (Lander and Botstein 1989). Consideration of only the genotyped individuals results in a biased estimate of the QTL effect. Haley-Knott regression (Haley and Knott 1992) generally provides a good approximation to standard interval mapping, but should be avoided in the case of selective genotyping, as it tends to produce inflated evidence for linkage (Feenstra et al. 2006).. Despite the common use of selective genotyping for QTL mapping and the extensive literature on significance thresholds for QTL mapping, we are not aware of any discussion of ...
Genome-wide studies of gene expression have successfully identified genetic variants that contribute to the variation of gene expression within populations [1-11]. The objective of genome-wide association studies (GWAS) is to map genotypic variation to phenotypic variation. Jansen and Nap [12] proposed extending the GWAS paradigm to deal with quantitative endophenotypes, e.g. RNA, protein and metabolite abundance in a cell. To date, consideration of RNA abundance has received most attention in the literature [1-11]. Those variants that affect gene expression are referred to as expression quantitative trait loci (eQTLs) of which thousands have been reported [1-11]. Most studies have focused on single nucleotide polymorphisms (SNPs).. The literature reports two classes of eQTL, cis-acting SNPs and trans-acting SNPs. Cis-acting SNPs lie within a gene or near the transcription start or stop site of a gene and correlate with the expression of that gene. In contrast, trans-acting SNPs can lie anywhere ...
TY - JOUR. T1 - A model selection approach for the identification of quantitative trait loci in experimental crosses, allowing epistasis. AU - Manichaikul, Ani. AU - Moon, Jee Young. AU - Sen, Śaunak. AU - Yandell, Brian S.. AU - Broman, Karl W.. PY - 2009/3. Y1 - 2009/3. N2 - The identification of quantitative trait loci (QTL) and their interactions is a crucial step toward the discovery of genes responsible for variation in experimental crosses. The problem is best viewed as one of model selection, and the most important aspect of the problem is the comparison of models of different sizes. We present a penalized likelihood approach, with penalties on QTL and pairwise interactions chosen to control false positive rates. This extends the work ofBroman and Speed to allow for pairwise interactions among QTL. A conservative version of our penalized LOD score provides strict control over the rate of extraneous QTL and interactions; a more liberal criterion is more lenient on interactions but seeks ...
TY - JOUR. T1 - Identification of quantitative trait locus for abscisic acid responsiveness on chromosome 5A and association with dehydration tolerance in common wheat seedlings. AU - Iehisa, Julio C.M.. AU - Matsuura, Takakazu. AU - Mori, Izumi C.. AU - Takumi, Shigeo. PY - 2014/1/1. Y1 - 2014/1/1. N2 - The phytohormone abscisic acid (ABA) plays important roles in response to environmental stress as well as in seed maturation and dormancy. In common wheat, quantitative trait loci (QTLs) for ABA responsiveness at the seedling stage have been reported on chromosomes 1B, 2A, 3A, 6D and 7B. In this study, we identified a novel QTL for ABA responsiveness on chromosome 5A using an F2 population derived from a cross between the common wheat cultivar Chinese Spring (CS) and a chromosome substitution line of CS with chromosome 5A of cultivar Hope (Hope5A). This QTL was found in a similar chromosomal region to previously reported QTLs for drought tolerance and seed dormancy. Physiological ...
Soybean [Glycine max (L.) Merr.] is an important oilseed crop which produces about 30 %of the worlds edible vegetable oil. The quality of soybean oil is determined by its fatty acid composition. Soybean oil high in oleic and low in linolenic fatty acids is desirable for human consumption and other uses. The objectives of this study were to identify quantitative trait loci (QTLs) for unsaturated fatty acids and to evaluate the genetic effects of single QTL and QTL combinations in soybean. A population of recombinant inbred lines derived from the cross of SD02-4-59 X A02-381100 was evaluated for fatty acid content in seven environments. In total, 516 polymorphic single nucleotide polymorphism markers, 477 polymorphic simple sequence repeat markers and three GmFAD3 geneswere used to genotype the mapping population. By using the composite interval mapping and/or the interval mapping method, a total of 15 QTLs for the three unsaturated fatty acids were detected in more than two environments. Two QTLs for
Plant disease resistance governed by quantitative trait loci (QTL) is predicted to be effective against a broad spectrum of pathogens and long lasting. Use of these QTL to improve crop species, however, is hindered because the genes contributing to the trait are not known. Five disease resistance QTL that colocalized with defense response genes were accumulated by marker-aided selection to develop blast-resistant varieties. One advanced backcross line carrying the major-effect QTL on chromosome (chr) 8, which included a cluster of 12 germin-like protein (OsGLP) gene members, exhibited resistance to rice (Oryza sativa) blast disease over 14 cropping seasons. To determine if OsGLP members contribute to resistance and if the resistance was broad spectrum, a highly conserved portion of the OsGLP coding region was used as an RNA interference trigger to silence a few to all expressed chr 8 OsGLP family members. Challenge with two different fungal pathogens (causal agents of rice blast and sheath ...
Deerhake, Marion Elizabeth, "Quantitative trait loci analysis of blood pressure in an eight intercross mouse study" (2008). Summer and Academic Year Student Reports. 2234 ...
MalaCards based summary : Bone Mineral Density Quantitative Trait Locus 12, is also known as bone mineral density qtl 12, osteoporosis. An important gene associated with Bone Mineral Density Quantitative Trait Locus 12 is UGT2B17 (UDP Glucuronosyltransferase Family 2 Member B17). Affiliated tissues include bone ...
MalaCards based summary : Bone Mineral Density Quantitative Trait Locus 11, also known as bmnd11, is related to osteoporosis. An important gene associated with Bone Mineral Density Quantitative Trait Locus 11 is BMND11 (Bone Mineral Density QTL 11). Affiliated tissues include bone ...
A four-stage approach was used to analyse epistasis based on the pre-corrected phenotypes where SNP genotypes were fitted as fixed factors: 1) single SNP regression to identify qSNPs (see above); 2) detect qSNP × qSNP pairs [9]; 3) detect qSNP × non-qSNP pairs; 4) detect non-qSNP × non-qSNP pairs. Nested tests were used to identify significant epistatic pairs; the first test compares the full model (y = μ+SNP1+SNP2+SNP1 *SNP2+e) with the NULL model (y = μ+e); the second test compares the full model with the two-SNP model (y = μ+SNP1+SNP2+e) (i.e. epistasis test). Only pairs that were significant for the first test enter the epistasis test. When either SNP1 or SNP2 is a qSNP, the first test is changed to ensure the full model is better than the single SNP model (y = μ+qSNP +e) before the epistasis test. When both SNP1 and SNP2 are qSNPs, only the epistasis test is needed. To avoid spurious interactions between closely located SNPs an arbitrary minimum distance of 10 cM was applied to any ...
Beef cattle require dietary minerals for optimal health, production and reproduction. Concentrations of minerals in tissues are at least partly genetically determined. Mapping genomic regions that affect the mineral content of bovine longissimus dorsi muscle can contribute to the identification of genes that control mineral balance, transportation, absorption and excretion and that could be associated to metabolic disorders. We applied a genome-wide association strategy and genotyped 373 Nelore steers from 34 half-sib families with the Illumina BovineHD BeadChip. Genome-wide association analysis was performed for mineral content of longissimus dorsi muscle using a Bayesian approach implemented in the GenSel software. Muscle mineral content in Bos indicus cattle was moderately heritable, with estimates ranging from 0.29 to 0.36. Our results suggest that variation in mineral content is influenced by numerous small-effect QTL (quantitative trait loci) but a large-effect QTL that explained 6.5% of the
Three quantitative trait loci (QTL) located on chromosome 1H, single QTL located on chromosomes 1H, 2H, 4H, 5H and 7H, were identified to be responsible for salinity tolerance under different environments. Waterlogging stress, daylight length and temperature showed significant effects on barley salinity tolerance. The QTL for salinity tolerance mapped on chromosomes 4H and 7H, QSlwd.YG.4H, QSlwd.YG.7H and QSlww.YG.7H were only identified in winter trials, while the QTL on chromosome 2H QSlsd.YG.2H and QSlsw.YG.2H were only detected in summer trials. Genes associated with flowering time were found to pose significant effects on the salinity QTL mapped on chromosomes 2H and 5H in summer trials. Given the fact that the QTL for salinity tolerance QSlsd.YG.1H and QSlww.YG.1H-1 reported here have never been considered in the literature, this warrants further investigation and evaluation for suitability to be used in breeding programs.. ...
Wheat (Triticum aestivum L.) grain quality traits that are controlled by quantitative traits loci (QTL) define suitable growing areas and potential end-use products of a wheat cultivar. To dissect QTL for these traits including protein content (GPC); test weight (TW); single kernel characterization system (SKCS)-estimated kernel weight (SKW); kernel diameter (KD); kernel hardness measured by near-infrared reflectance spectroscopy (NIRS) hardness index (NHI); and SKCS-hardness index (SHI), a high-density genetic map with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers was developed using recombinant inbred lines (RILs) derived from Ning7840 x Clark. The RILs were evaluated for these quality traits in seven Oklahoma environments from 2001 to 2003. A total of 41 QTL with additive effects on different traits were mapped on most wheat chromosomes, excluding 1A, 2A, 3D, 4D, 6D, and 7B. Seven chromosome regions showed either tightly linked QTL or QTL with pleiotropic ...
Breeding chickens for heat tolerance is desirable. The F18 and F19 generations of a broiler by Fayoumi advanced intercross line (AIL) was used to facilitate fine mapping of QTL. Three major phenotype collection phases were: pre-heat, acute heat, and chronic heat, with birds being exposed to daily heat cycles from 22 to 28 days of age. Body temperature was measured at all three phases; body weight at pre-heat and chronic heat phases. Breast muscle yield (as percentage of body weight) was measured after necropsy at d 28. Feed digestibility was assayed from ileal content collected at d 28. Birds were genotyped using a 600K Affymetrix chicken SNP array. Using GenSel significant QTL were found for each of the measured traits, indicating the feasibility of improving performance under hot conditions by genomic selection. This is the first GWAS using this novel AIL of chickens under heat stress.. ...
Differences in floral morphologies affect pollination behaviour in many flowering plants. In the genus Oryza, several differences in the size of floral organs are known. In this study, we focused on the differences in the size of floral organs between common cultivated rice, Oryza sativa L. and its wild ancestor, O. rufipogon. We compared floral morphologies between cultivated rice O. sativa cv. Nipponbare and O. rufipogon W630. We first evaluated temporal changes in filament and anther lengths. W630 had longer filaments with rapid elongation within 15 min after spikelet opening. W630 also had longer anthers than Nipponbare, and size of anther was consistent throughout all time examined. We also analysed other six floral traits, and found that W630 had higher stigma and style length, as well as lemma and palea length, but lower lemma and palea width. Quantitative trait locus (QTL) analysis was performed to identify the loci controlling these floral traits, using backcross recombinant inbred
The whitebacked planthopper (WBPH), Sogatella furcifera Horváth, is a serious rice pest in Asia. Ovicidal resistance is a natural rice defense mechanism against WBPH and is characterized by the formation of watery lesions (WLs) and increased egg mortality (EM) at the WBPH oviposition sites. This study aimed to understand the genetic and molecular basis of rice ovicidal resistance to WBPH by combining genetic and genomic analyses. First, the ovicidal trait in doubled haploid rice lines derived from a WBPH-resistant cultivar (CJ06) and a WBPH-susceptible cultivar (TN1) were phenotyped based on the necrotic symptoms of the leaf sheaths and EM. Using a constructed molecular linkage map, 19 quantitative trait loci (QTLs) associated with WLs and EM were identified on eight chromosomes. Of them, qWL6 was determined to be a major QTL for WL. Based on chromosome segment substitution lines and a residual heterozygous population, a high-resolution linkage analysis further defined the qWL6 locus to a 122-kb region
Detecting both the majors genes that control the phenotypic mean and those controlling phenotypic variance has been raised in quantitative trait loci analysis. In order to mapping both kinds of genes, we applied the idea of the classic Haley-Knott regression to double generalized linear models. We performed both kinds of quantitative trait loci detection for a Red Jungle Fowl x White Leghorn F2 intercross using double generalized linear models. It is shown that double generalized linear model is a proper and efficient approach for localizing variance-controlling genes. We compared two models with or without fixed sex effect and prefer including the sex effect in order to reduce the residual variances. We found that different genes might take effect on the body weight at different time as the chicken grows.. ...
The genetics of sexual isolation, behavioral differences between species that prevent mating, is understood poorly. Pheromonal differences between species can influence sexual isolation in many animals and in some cases a single locus can cause large functional changes in pheromonal mating signals. Drosophila cuticular hydrocarbons (CHCs) can function as pheromones and consequently affect mate recognition. In a previous study of the two major CHCs in females that affect mating discrimination between Drosophila simulans and D. sechellia, quantitative trait loci (QTL) were identified on the X and third chromosome, and a few candidate genes were potentially implicated. Here we specifically test candidate genes for CHC biosynthesis and determine the genetic architecture of four additional CHCs that differ in abundance between D. simulans and D. sechellia females. The same QTL, and new ones, were found for additional CHCs. By examining all these CHCs and exploring their covariance, we were able to ascribe
Di Nicolantonio, R., Kostka, V., Kwitek, A., Jacob, H., Thomas, W.G. and Harrap, S.B. 2006, Fine mapping of Lvm1: a quantitative trait locus controlling heart size independently of blood pressure, Pulmonary pharmacology & therapeutics, vol. 19, no. 1, pp. 70-73, doi: 10.1016/j.pupt.2005.02.010. ...
Michaud, Amy Marie, "Identifying quantitative trait loci for hip axis geometry phenotypes in C57BL/6J X CAST/EiJ inbred mice." (2009). Summer and Academic Year Student Reports. 2279 ...
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Results The SLE-associated SNPs demonstrated more eQTLs in NCLs as compared to CLs (p=2.5x10-8). For a given SNP, the associated transcripts differed between cell types (p,0.001 for all 7 SNPs for discordance), suggesting that the same SNP resulted in different cellular events between the two monocyte subsets. Loci which shared a significant proportion of eQTL associations with each other in NCLs included TNFAIP3, IRF5, IRF7, PTPN22, and SPP1. In CLs, TNFAIP3 shared a large number of eQTLs with SPP1 and ITGAM, although SPP1 and ITGAM showed more limited overlap with each other. Thus, SLE-associated risk loci exert coordinated effects on gene expression within individual human monocytes, and the risk loci interact in different ways in different cell types. ...
The present study was undertaken to identify genes that influence LDL size properties. Although LDL size phenotype has been shown in many studies to be an important CVD risk factor, little is known about the genes that influence LDL size properties. In this study, we used gradient gel electrophoresis to measure the amount of cholesterol in each of 4 different LDL size fractions, and performed mixing experiments to show that LDL particles that differed in size and composition have similar chromogenicities for cholesterol staining (Figure 1⇑). For each of the 4 LDL size fractions, we found significant heritabilities, which ranged from 22% to 37% (Table 1⇑), suggesting the existence of 1 or more genes that influence each of the 4 fractions. These measures of LDL size fractions were also significantly influenced by several covariates, including age and sex. The LDL size fractions are related metabolically36 and they are significantly intercorrelated phenotypically (r2 values for the 6 possible ...
The nematode Caenorhabditis elegans has been extensively used to explore the relationships between complex traits, genotypes, and environments. Complex traits can vary across different genotypes of a species, and the genetic regulators of trait variation can be mapped on the genome using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) derived from genetically and phenotypically divergent parents. Most RILs have been derived from crossing two parents from globally distant locations. However, the genetic diversity between local C. elegans populations can be as diverse as between global populations and could thus provide means of identifying genetic variation associated with complex traits relevant on a broader scale. To investigate the effect of local genetic variation on heritable traits, we developed a new RIL population derived from 4 parental wild isolates collected from 2 closely located sites in France: Orsay and Santeuil. We crossed these 4 genetically diverse parental
Background: Epistasis (synergistic interaction) among SNPs governing gene expression is likely to arise withintranscriptional networks. However, the power to detect it is limited by the large number of combinations to betested and the modest sample sizes of most datasets. By limiting the interaction search space firstly to cis-trans andthen cis-cis SNP pairs where both SNPs had an independent effect on the expression of the most variabletranscripts in the liver and brain, we greatly reduced the size of the search space.Results: Within the cis-trans search space we discovered three transcripts with significant epistasis. Surprisingly, allinteracting SNP pairs were located nearby each other on the chromosome (within 290 kb-2.16 Mb). Despite theirproximity, the interacting SNPs were outside the range of linkage disequilibrium (LD), which was absent betweenthe pairs (r2 , 0.01). Accordingly, we redefined the search space to detect cis-cis interactions, where a cis-SNP waslocated within 10 Mb of the ...
Plant height (PH) and ear height (EH) are two very important agronomic traits related to the population density and lodging in maize. In order to better understand of the genetic basis of nature variation in PH and EH, two bi-parental populations and one genome-wide association study (GWAS) population were used to map quantitative trait loci (QTL) for both traits. Phenotypic data analysis revealed a wide normal distribution and high heritability for PH and EH in the three populations, and indicated that maize height is a highly polygenic trait. A total of 21 QTL for PH and EH in three common genomic regions (bin 1.05, 5.04/05, and 6.04/05) were identified by QTL mapping in the two bi-parental populations under multiple environments. Additionally, 41 single nucleotide polymorphisms (SNPs) were identified for PH and EH by GWAS, of which 29 SNPs were located in 19 unique candidate gene regions. Most of the candidate genes were related to plant growth and development. One QTL on Chromosome 1 was further
In this study, we evaluated conformation traits describing leg and feet condition, osteochondrosis score and bone mineral density, which are important in selection to reduce the risk of leg weakness in pigs. However, the genetics of LW-related traits is complex [12, 31]. A number of factors are known to influence the development of LW, such as nutrition imbalance, high body weight, rapid growth rate, bone and joint diseases, bad body and leg structure, and mechanical stress [11, 13]. Moreover, it has been reported that the degree of LW and OC may be related to the breed and sex of animals [32]. However, in our study there was no effect of gender on LW-related traits, which implies that frequencies of LW and OC vary and depend on the genetic background of the animals [33]. It has been reported that the Duroc pure breed shows the highest incidence of OC compared to other European pig breeds (Pietrain, Landrace and Yorkshire) [32]. Our data suggest that the unfavourable QTL allele for OC originates ...
Type 2 diabetes is a genetically heterogeneous disease involving insulin resistance, β-cell dysfunction, and increased glucose production by the liver. Identification of multiple QTLs suggests that there is a high degree of genetic heterogeneity of type 2 diabetes. To circumvent this limitation, we focused on a single large family, because those individuals likely share the same polymorphisms, thus minimizing genetic heterogeneity. Although environmental factors, such as physical activity and diet, also influence the development of type 2 diabetes and may interact with genetic effects, these measures were not collected, therefore future studies should further examine these effects.. Our results suggest that a gene located near D5S428 is responsible for variability in affection status. As we focused on a single family, the applicability of these findings to the general population is a concern. However, Lindsay et al. (29) identified tentative evidence of linkage (LOD = 1.5) ∼15 cM from our ...
Background: Over 90 regions of the genome have been associated with lung function to date, many of which have also been implicated in chronic obstructive pulmonary disease. Methods: We carried out meta-analyses of exome array data and three lung function measures: forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and the ratio of FEV1 to FVC (FEV1/FVC). These analyses by the SpiroMeta and CHARGE consortia included 60,749 individuals of European ancestry from 23 studies, and 7,721 individuals of African Ancestry from 5 studies in the discovery stage, with follow-up in up to 111,556 independent individuals. Results: We identified significant (P,2·8x10-7) associations with six SNPs: a nonsynonymous variant in RPAP1, which is predicted to be damaging, three intronic SNPs (SEC24C, CASC17 and UQCC1) and two intergenic SNPs near to LY86 and FGF10. Expression quantitative trait loci analyses found evidence for regulation of gene expression at three signals and implicated ...
TY - JOUR. T1 - The association of cell cycle checkpoint 2 variants and kidney function. T2 - Findings of the family blood pressure program and the atherosclerosis risk in communities study. AU - Franceschini, Nora. AU - North, Kari E.. AU - Arnett, Donna. AU - Pankow, James S.. AU - Chung, Jay H.. AU - Baird, Lisa. AU - Leppert, Mark F.. AU - Eckfeldt, John H.. AU - Boerwinkle, Eric. AU - Gu, C. Charles. AU - Lewis, Cora E.. AU - Myers, Richard H.. AU - Turner, Stephen T.. AU - Weder, Alan. AU - Kao, W. H Linda. AU - Mosley, Thomas H.. AU - Chakravarti, Aravinda. AU - Kramer, Holly. AU - Zhang, Jinghui. AU - Hunt, Steven C.. PY - 2009/5. Y1 - 2009/5. N2 - Background: Recent experimental evidence suggests that DNA damage and cell cycle regulatory proteins are involved in kidney injury and apoptosis. The checkpoint 2 gene (CHEK2) is an important transducer in DNA damage signaling pathways in response to injury, and therefore, CHEK2 variants may affect susceptibility to kidney disease.MethodsWe ...
Haplotype reconstruction in progeny from multiparent crosses requires specialized methods and software. These methods have evolved significantly over the past decade and we expect to see a continued increase in the overlap between heterozygous model systems and human genetic mapping. HAPPY, one of the first software packages developed for haplotype reconstruction in heterogeneous stocks, uses genotype calls and a dynamic programming algorithm for haplotype reconstruction (Mott et al. 2000). Our HMM implementation is more complex than dynamic programming but it provides probabilistic estimates of haplotypes (and diplotypes) that we can use to account for genotype uncertainty in genome scans. The current implementation is based on the marginal diplotype state probabilities. Implementation of a globally optimal reconstruction (Van der Bliek et al. 1988; Viterbi 1967) is planned for a future release of DOQTL.. We have implemented an EM algorithm to estimate HMM parameters directly from genotype or ...
It has been shown [14] that for a two-way cross and ignoring selection, the allele substitution effects for QTL or markers in one parental breed depend on the allele frequencies in the other parental breed. Thus, in the computation of substitution effects, failure to use the appropriate allele frequencies may result in a loss of response to selection. Dekkers [23] showed that, with the availability of only purebred data, selection within a breed using QTL allele substitution effects that are based on the allele frequencies from the opposite breed gave substantially greater response to selection than using allele frequencies from the same breed.. In the additive model, a single substitution effect was estimated for each SNP, assuming it is the same for both parental breeds. Selection on GEBV derived using such allele substitution effects is expected to fix the favorable allele in both breeds (Figure 6a). Exceptions to this could be genetic drift or the marker and QTL being in LD with opposite ...
The study of Population genetics and Statistical genetics in order to link variation in genotype with a variation in phenotype. In other words, it is desirable to discover the genetic basis of a measurable trait, a quantitative trait, that is under polygenic control. A genome region that is responsible for a continuous trait is called Quantitative trait locus (QTL). The study of QTLs become feasible by using molecular markers and measuring traits in populations, but their mapping needs the obtaining of a population from an experimental crossing, like an F2 or Recombinant inbred strains/lines (RILs). To scan for QTLs regions in a genome, a gene map based on linkage have to be built. Some of the best-known QTL mapping algorithms are Interval Mapping, Composite Interval Mapping, and Multiple Interval Mapping.[29] However, QTL mapping resolution is impaired by the amount of recombination assayed, a problem for species in which it is difficult to obtain large offspring. Furthermore, allele diversity ...
Solanesol is a high value 45-carbon, unsaturated, all-trans-nonaprenol isoprenoid. Recently solanesol has received particular attention because of its utility, both in its own right and as a precursor in the production of numerous compounds used in the treatment of disease states. Solanesol is found mainly in solanaceous crops such as potato, tomato, tobacco and pepper where it accumulates in the foliage. There is considerable potential to explore the extraction of solanesol from these sources as a valuable co-product. In this study we have characterised the genetic variation in leaf solanesol content in a biparental, segregating diploid potato population. We demonstrate that potato leaf solanesol content is genetically controlled and identify several quantitative trait loci associated with leaf solanesol content. Transient over-expression of genes from the methylerythritol 4-phosphate (MEP) and mevalonic acid (MVA) pathways, either singly or in combination, resulted in enhanced accumulation of
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Genetic architecture of the quantitative traits is an important aspect for understanding the sustained response of selection and also for predicting the disease risk. In regards to the distribution of effect of variants underlying the quantitative traits, Fisher (1918) proposed a simple explanation, termed as the infinitesimal model, where the quantitative traits are composed by…
The objective of this study was to identify single-nucleotide polymorphisms using a bovine chromosome 14 high-density SNP panel after accounting for the effect of DGAT1. Linkage disequilibrium information and sire heterozygosity were used to select m
Chromosomal regions of bovine chromosome one were scanned for the detection and mapping of segregating QTL influencing preweaning withers height, hip height, hip width, body length, chest width, chest depth, shoulder width, lumbar width, thurl width, pin bone width, rump length, cannon circumference, heart girth, abdominal width and abdominal girth. QTL analysis was performed by genotyping 132 half-sib progeny of 5 Japanese Black sires using 108 microsatellite DNA markers. Genotyped data on progeny and their sires were combined in a multi-point approach to calculate Identity-By-Descent (IBD) probability coefficients of inheriting allele 1 or 2 from the sire at specific chromosomal locations.The phenotypic data on progeny were regressed on these IBD coefficients in a within-common-parent regression analysis. A linear model containing the fixed effects of sex, parity and season of birth as well as age as a covariate, was fitted to the IBD coefficients and phenotypic data. Data were analyzed using ...
A general experimental design that allows mapping of a quantitative trait locus (QTL) into a 1-cM interval is presented. The design consists of a series of strains, termed
Among all cereals, rice is highly sensitive to cold stress, especially at the germination stage, which adversely impacts its germination ability, seed vigor, crop stand establishment, and, ultimately, grain yield. The dissection of novel quantitative trait loci (QTLs) or genes conferring a low-temperature germination (LTG) ability can significantly accelerate cold-tolerant rice breeding to ensure the wide application of rice cultivation through the direct seeding method. In this study, we identified 11 QTLs for LTG using 144 recombinant inbred lines (RILs) derived from a cross between a cold-tolerant variety, Lijiangxintuanheigu (LTH), and a cold-sensitive variety, Shennong265 (SN265). By resequencing two parents and RIL lines, a high-density bin map, including 2,828 bin markers, was constructed using 123,859 single-nucleotide polymorphisms (SNPs) between two parents. The total genetic distance corresponding to all 12 chromosome linkage maps was 2,840.12 cm. Adjacent markers were marked by an average
by Barbara Stranger, Qiyuan Li, Ji-Heui Seo, Aaron McKenna, Itsik Peer, Thomas LaFramboise, Myles Brown, Svitlana Tyekucheva, Matthew L. Freedman Germline determinants of gene expression in tumors are infrequently studied due to the complexity of transcript regulation caused by somatically acquired alterations. We performed expression quantitative trait locus (eQTL)-based analyses using the multi-level information provided in The Cancer Genome Atlas (TCGA). Of the factors we measured, cis-acting eQTLs accounted for 1.2% of the total variation of tumor gene expression, while somatic copy-number alteration and CpG methylation accounted for 7.3% and 3.3%, respectively. eQTL analyses of 15 previously reported breast cancer risk loci resulted in the discovery of three variants that are significantly associated with transcript levels (false discovery rate [FDR] < 0.1). Our trans-based analysis identified an additional three risk loci to act through ESR1, MYC, and KLF4. These findings provide a more ...
Genome-wide association studies have identified many genetic variants associated with complex traits. However, at only a minority of loci have the molecular mechanisms mediating these associations been characterized. In parallel, whereas cis regulatory patterns of gene expression have been extensively explored, the identification of trans regulatory effects in humans has attracted less attention. Here we show that the type 2 diabetes and high-density lipoprotein cholesterol-associated cis-acting expression quantitative trait locus (eQTL) of the maternally expressed transcription factor KLF14 acts as a master trans regulator of adipose gene expression. Expression levels of genes regulated by this trans-eQTL are highly correlated with concurrently measured metabolic traits, and a subset of the trans-regulated genes harbor variants directly associated with metabolic phenotypes. This trans-eQTL network provides a mechanistic understanding of the effect of the KLF14 locus on metabolic disease risk and offers