Quantitative trait loci associated with maximal exercise endurance in mice

2007 ◽  
Vol 103 (1) ◽  
pp. 105-110 ◽  
Author(s):  
J. Timothy Lightfoot ◽  
Michael J. Turner ◽  
Amy Kleinfehn Knab ◽  
Anne E. Jedlicka ◽  
Tomohiro Oshimura ◽  
...  
Keyword(s):  
Quantitative Trait ◽  
Genetic Factors ◽  
Maximal Exercise ◽  
Inbred Mouse ◽  
Inbred Strains ◽  
Significant Quantitative Trait Locus ◽  
Chromosome 8 ◽  
Entire Cohort ◽  
Exercise Endurance ◽  
Trait Locus

The role of genetics in the determination of maximal exercise endurance is unclear. Six- to nine-week-old F2 mice ( n = 99; 60 female, 39 male), derived from an intercross of two inbred strains that had previously been phenotyped as having high maximal exercise endurance (Balb/cJ) and low maximal exercise endurance (DBA/2J), were treadmill tested to estimate exercise endurance. Selective genotyping of the F2 cohort ( n = 12 high exercise endurance; n = 12 low exercise endurance) identified a significant quantitative trait locus (QTL) on chromosome X (53.7 cM, DXMit121) in the entire cohort and a suggestive QTL on chromosome 8 (36.1 cM, D8Mit359) in the female mice. Fine mapping with the entire F2 cohort and additional informative markers confirmed and narrowed the QTLs. The chromosome 8 QTL ( EE8 F) is homologous with two suggestive human QTLs and one significant rat QTL previously linked with exercise endurance. No effect of sex ( P = 0.33) or body weight ( P = 0.79) on exercise endurance was found in the F2 cohort. These data indicate that genetic factors in distinct chromosomal regions may affect maximal exercise endurance in the inbred mouse. Whereas multiple genes are located in the identified QTL that could functionally affect exercise endurance, this study serves as a foundation for further investigations delineating the identity of genetic factors influencing maximum exercise endurance.

scholarly journals Multiple alleles for tuber shape in diploid potato detected by qualitative and quantitative genetic analysis using RFLPs.

Genetics ◽  
1994 ◽  
Vol 137 (1) ◽  
pp. 303-309 ◽  
Author(s):  
H J Van Eck ◽  
J M Jacobs ◽  
P Stam ◽  
J Ton ◽  
W J Stiekema ◽  
...  
Keyword(s):  
Qtl Mapping ◽  
Quantitative Trait ◽  
Genetic Factors ◽  
Inbred Strains ◽  
Width Ratio ◽  
Tuber Shape ◽  
Multiple Alleles ◽  
Length Polymorphisms ◽  
Trait Locus ◽  
Diploid Level

Abstract Tuber shape in potato is commonly regarded as displaying continuous variation, yet at the diploid level phenotypes can be discerned visually, having round or long tubers. Inheritance of qualitative tuber shape can be explained by a single locus Ro, round being dominant to long. With restriction fragment length polymorphisms (RFLPs) the Ro locus was mapped on chromosome 10. Tuber shape was also studied as a quantitative trait, using the length/width ratio as trait value. The estimated broad sense heritability was h2 = 0.80. The morphologically mapped Ro locus explained 75% of the genetic variation, indicating the presence of a major quantitative trait locus (QTL) at the Ro locus and minor genetic factors. RFLP alleles linked with Ro alleles were used to divide the progeny into four genotypic classes: RofemaleRomale:Rofemalero:roRomale:roro = 1:1:1:1. The recessive ro allele is identical by descent in both parents. The significantly different effects (P = 0.0157) of the non-identical alleles Rofemale and Romale provided evidence for multiallelism at the Ro locus. Linkage mapping of the Ro locus was compared with QTL mapping. Only those markers which are polymorphic in both parents allow accurate QTL mapping when genetic factors segregate from both parents. This finding applies to QTL mapping in all outbreeders without homozygous inbred strains.

scholarly journals Mouse Susceptibility to Anthrax Lethal Toxin Is Influenced by Genetic Factors in Addition to Those Controlling Macrophage Sensitivity

2004 ◽  
Vol 72 (8) ◽  
pp. 4439-4447 ◽  
Author(s):  
Mahtab Moayeri ◽  
Nathaniel W. Martinez ◽  
Jason Wiggins ◽  
Howard A. Young ◽  
Stephen H. Leppla
Keyword(s):  
Genetic Factors ◽  
Inbred Mouse ◽  
Inbred Strains ◽  
Lethal Toxin ◽  
Cytokine Response ◽  
Mouse Strains ◽  
Anthrax Lethal Toxin ◽  
Toll Like Receptor 4 ◽  
Oxide Synthase

ABSTRACT Bacillus anthracis lethal toxin (LT) produces symptoms of anthrax in mice and induces rapid lysis of macrophages (Mφ) derived from certain inbred strains. We used nine inbred strains and two inducible nitric oxide synthase (iNOS) knockout C57BL/6J strains polymorphic for the LT Mφ sensitivity Kif1C locus to analyze the role of Mφ sensitivity (to lysis) in LT-mediated cytokine responses and lethality. LT-mediated induction of cytokines KC, MCP-1/JE, MIP-2, eotaxin, and interleukin-1β occurred only in mice having LT-sensitive Mφ. However, while iNOS knockout C57BL/6J mice having LT-sensitive Mφ were much more susceptible to LT than the knockout mice with LT-resistant Mφ, a comparison of susceptibilities to LT in the larger set of inbred mouse strains showed a lack of correlation between Mφ sensitivity and animal susceptibility to toxin. For example, C3H/HeJ mice, harboring LT-sensitive Mφ and having the associated LT-mediated cytokine response, were more resistant than mice with LT-resistant Mφ and no cytokine burst. Toll-like receptor 4 (Tlr4)-deficient, lipopolysaccharide-nonresponsive mice were not more resistant to LT. We also found that CAST/Ei mice are uniquely sensitive to LT and may provide an economical bioassay for toxin-directed therapeutics. The data indicate that while the cytokine response to LT in mice requires Mφ lysis and while Mφ sensitivity in the C57BL/6J background is sufficient for BALB/cJ-like mortality of that strain, the contribution of Mφ sensitivity and cytokine response to animal susceptibility to LT differs among other inbred strains. Thus, LT-mediated lethality in mice is influenced by genetic factors in addition to those controlling Mφ lysis and cytokine response and is independent of Tlr4 function.

Identification of RAPD markers for percent hull in oat

Genome ◽  
1997 ◽  
Vol 40 (6) ◽  
pp. 873-878 ◽  
Author(s):  
P. S. Ronald ◽  
G. A. Penner ◽  
P. D. Brown ◽  
A. Brûlé-Babel
Keyword(s):  
Quantitative Trait Locus ◽  
Quantitative Trait ◽  
Genetic Factors ◽  
Bulked Segregant Analysis ◽  
Multiple Time ◽  
Test Statistics ◽  
Marker Loci ◽  
Correct Determination ◽  
Trait Locus

Percent hull is an important physical parameter of oat grain quality, but it is affected by environment. Multiple time-consuming evaluations are required to obtain a correct determination of phenotype. The application of marker-assisted selection for the genes involved would greatly simplify the identification of desirable oat genotypes. Bulked segregant analysis, with selected progeny lines derived from a cross between Cascade and AC Marie (30 and 23% hull, respectively), was used to identify randomly amplified polymorphic DNA markers linked to genetic factors controlling primary kernel hull percentage in oat. Twelve polymorphisms, identified between bulks, were tested for linkage to genetic factors controlling hull percentage by genotyping 80 randomly selected F2-derived F8 lines from the progeny population. Three markers showed significant test statistics for quantitative trait locus effects, when tested with primary kernel percent hull data from two environments. Together, the unlinked marker loci OPC13800, OPD20600, and OPK71300 explained approximately 41% of the genetic variance in primary kernel percent hull, after accounting for the main effect of environment.Key words: Avena sativa, hull percentage, bulked segregant analysis, quantitative trait locus.

A quantitative trait locus for cold tolerance at the booting stage on rice chromosome 8

2007 ◽  
Vol 115 (5) ◽  
pp. 593-600 ◽  
Author(s):  
Makoto Kuroki ◽  
Koji Saito ◽  
Shuichi Matsuba ◽  
Narifumi Yokogami ◽  
Hiroyuki Shimizu ◽  
...  
Keyword(s):  
Quantitative Trait Locus ◽  
Cold Tolerance ◽  
Quantitative Trait ◽  
Rice Chromosome ◽  
Chromosome 8 ◽  
Booting Stage ◽  
Trait Locus

scholarly journals Genomic Locus Modulating IOP in the BXD RI Mouse Strains

2017 ◽  
Author(s):  
Rebecca King ◽  
Ying Li ◽  
Jiaxing Wang ◽  
Felix L. Struebing ◽  
Eldon E. Geisert
Keyword(s):  
Candidate Genes ◽  
Quantitative Trait ◽  
Significant Quantitative Trait Locus ◽  
Interval Mapping ◽  
Mouse Strains ◽  
Genomic Locus ◽  
Quantitative Trait Analysis ◽  
Significant Locus ◽  
Trait Locus ◽  
Different Strains

AbstractPurposeIntraocular pressure (IOP) is the primary risk factor for developing glaucoma. The present study examines genomic contribution to the normal regulation of IOP in the mouse.MethodsThe BXD recombinant inbred (RI) strain set was used to identify genomic loci modulating IOP. We measured the IOP from 532 eyes from 33 different strains. The IOP data will be subjected to conventional quantitative trait analysis using simple and composite interval mapping along with epistatic interactions to define genomic loci modulating normal IOP.ResultsThe analysis defined one significant quantitative trait locus (QTL) on Chr.8 (100 to 106 Mb). The significant locus was further examined to define candidate genes that modulate normal IOP. There are only two good candidate genes within the 6 Mb over the peak, Cdh8 (Cadherin 8) and Cdh11 (Cadherin 11). Expression analysis on gene expression and immunohistochemistry indicate that Cdh11 is the best candidate for modulating the normal levels of IOP.ConclusionsWe have examined the genomic regulation of IOP in the BXD RI strain set and found one significant QTL on Chr. 8. Within this QTL that are two potential candidates for modulating IOP with the most likely gene being Cdh11.

scholarly journals A novel genetic locus modulates infarct volume independently of the extent of collateral circulation

2013 ◽  
Vol 45 (17) ◽  
pp. 751-763 ◽  
Author(s):  
Pei-Lun Chu ◽  
Sehoon Keum ◽  
Douglas A. Marchuk
Keyword(s):  
Ischemic Stroke ◽  
Mouse Model ◽  
Candidate Genes ◽  
Genetic Factors ◽  
Infarct Volume ◽  
Inbred Strains ◽  
Chromosome 8 ◽  
Phenotypic Variance ◽  
Collateral Vessel ◽  
Vessel Anatomy

In the mouse model of permanent, middle cerebral artery occlusion, infarct volume varies widely across inbred strains but generally is inversely correlated with collateral vessel number. However, we also observed certain mouse strains that share similar collateral vessel anatomy but exhibit significantly different infarct volume. To identify genetic factors determining infarct volume in a collateral vessel-independent manner, we performed quantitative trait locus analysis on a F2 cross between C57BL/6J and C3H/HeJ strains. We mapped four novel loci ( Civq4 through Civq7) that modulate infarct volume. Civq4, on chromosome 8, is the strongest locus (logarithm of the odds 9.8) that contributes 21% of the phenotypic variance of infarct volume in the cross. The Civq4 and Civq6 loci represent transgressive B6 alleles that render animals susceptible to larger infarcts. Based on genomic sequence and microarray analyses, we propose candidate genes for the Civq4 locus. By selecting inbred strains with similar collateral vessel anatomy but that vary significantly in infarct volume, we have mapped four loci determining infarct volume in a mouse model of ischemic stroke. Two of the loci appear to modulate infarct volume through a collateral vessel-independent mechanism. Based on strain-specific sequence variants and differences in transcript levels, Msr1 and Mtmr7 appear to be strong candidate genes for Civq4. Identifying the underlying genetic factors of these loci will elucidate the genetic architecture response to cerebral ischemia, shed new light on disease mechanisms of ischemic stroke, and identify potential therapeutic targets for clinical applications.

Quantitative trait locus and haplotype mapping in closely related inbred strains identifies a locus for open field behavior

2010 ◽  
Vol 21 (5-6) ◽  
pp. 231-246 ◽  
Author(s):  
Amy F. Eisener-Dorman ◽  
Laura Grabowski-Boase ◽  
Brian M. Steffy ◽  
Tim Wiltshire ◽  
Lisa M. Tarantino
Keyword(s):  
Quantitative Trait Locus ◽  
Open Field ◽  
Quantitative Trait ◽  
Inbred Strains ◽  
Open Field Behavior ◽  
Field Behavior ◽  
Trait Locus ◽  
Haplotype Mapping

scholarly journals Genetic variation in the promoter of an R2R3−MYB transcription factor determines fruit malate content in apple (Malus domestica Borkh.)

2021 ◽  
Author(s):  
Dongjie Jia ◽  
Peng Wu ◽  
Fei Shen ◽  
Wei Li ◽  
Xiaodong Zheng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Malus Domestica ◽  
Quantitative Trait ◽  
Molecular Mechanisms ◽  
Chromosome 8 ◽  
Myb Transcription Factor ◽  
Nucleotide Polymorphisms ◽  
Malus Domestica Borkh ◽  
Trait Locus ◽  
R2r3 Myb

Abstract Deciphering the mechanism of malate accumulation in apple (Malus domestica Borkh.) fruits can help to improve their flavor quality and enhance their benefits for human health. Here, we analyzed malate content as a quantitative trait that is determined mainly by genetic effects. In a previous study, we identified an R2R3−MYB transcription factor named MdMYB44 that was a candidate gene in qtl08.1 (quantitative trait locus mapped to chromosome 8) of fruit malate content. In the present study, we established that MdMYB44 negatively regulates fruit malate accumulation by repressing the promoter activity of the malate-associated genes Ma1 (Al-Activated Malate Transporter 9), Ma10 (P-type ATPase 10), MdVHA-A3 (V-type ATPase A3), and MdVHA-D2 (V-type ATPase D2). Two single-nucleotide polymorphisms (SNPs) in the MdMYB44 promoter, SNP A/G and SNP T/−, were experimentally shown to associate with fruit malate content. The TATA-box in the MdMYB44 promoter in the presence of SNP A enhances the basal activity of the MdMYB44 promoter. The binding of a basic-helix–loop–helix transcription factor MdbHLH49 to the MdMYB44 promoter was enhanced by the presence of SNP T, leading to increased MdMYB44 transcript levels and reduced malate accumulation. Furthermore, MdbHLH49 interacts with MdMYB44 and enhances MdMYB44 activity. The two SNPs could be used in combination to select for sour or non-sour apples, providing a valuable tool for the selection of fruit acidity by the apple breeding industry. This research is important for understanding the complex molecular mechanisms of fruit malate accumulation and accelerating the development of germplasm innovation in apple species and cultivars.

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