scholarly journals A new strategy of heterosis research in mice – approach and results on chromosome 19

1999 ◽  
Vol 42 (1) ◽  
pp. 103-110 ◽  
Author(s):  
C. Brunsch ◽  
U. Philipp ◽  
P. Reinecke ◽  
G. Moser ◽  
H. Geldermann ◽  
...  
Keyword(s):  
Litter Size ◽  
Average Distance ◽  
Inbred Strains ◽  
Phenotypic Variance ◽  
Chromosome 19 ◽  
Degree Of Dominance ◽  
New Strategy ◽  
F2 Generation ◽  
Selection Of ◽  
Qtl Effects

Abstract. The following steps were performed to analyse heterosis and QTL effects in litter size of mice: intercross of mouse inbred strains C57BL/6J and Balb/cJ in order to produce a F2 generation with 948 female animals; selection of trait groups with extreme high ((13 offspring) and extreme low litter size (5 offspring)); typing of 56 microsatellites with an average distance of 32 cM; detection of different chromosome regions with associations to heterosis in litter size. Chromosome 19 was associated to heterosis in litter size. Additional animals with extreme high and low litter sizes were then typed for four DNA markers on chromosome 19 and used for QTL mapping. A QTL was identified for litter size in segment D19Mit28 &ndash: D19Mit99 with a maximum at 15 cM (p ≤ 0.05). The QTL explains about 11% of the phenotypic variance in the F2 generation. With a degree of dominance of 4.09 the QTL shows that superdominance can explain heterosis in litter size.

scholarly journals Integration and Modularity of Quantitative Trait Locus Effects on Geometric Shape in the Mouse Mandible

Genetics ◽  
2004 ◽  
Vol 166 (4) ◽  
pp. 1909-1921
Author(s):  
Christian Peter Klingenberg ◽  
Larry J Leamy ◽  
James M Cheverud
Keyword(s):  
Quantitative Trait ◽  
Parametric Bootstrap ◽  
Interval Mapping ◽  
Procrustes Analysis ◽  
Bootstrap Test ◽  
Mandible Shape ◽  
Trait Locus ◽  
F2 Generation ◽  
Analysis Interval ◽  
Qtl Effects

Abstract The mouse mandible has long served as a model system for complex morphological structures. Here we use new methodology based on geometric morphometrics to test the hypothesis that the mandible consists of two main modules, the alveolar region and the ascending ramus, and that this modularity is reflected in the effects of quantitative trait loci (QTL). The shape of each mandible was analyzed by the positions of 16 morphological landmarks and these data were analyzed using Procrustes analysis. Interval mapping in the F2 generation from intercrosses of the LG/J and SM/J strains revealed 33 QTL affecting mandible shape. The QTL effects corresponded to a variety of shape changes, but ordination or a parametric bootstrap test of clustering did not reveal any distinct groups of QTL that would affect primarily one module or the other. The correlations of landmark positions between the two modules tended to be lower than the correlations between arbitrary subsets of landmarks, indicating that the modules were relatively independent of each other and confirming the hypothesized location of the boundary between them. While these results are in agreement with the hypothesis of modularity, they also underscore that modularity is a question of the relative degrees to which QTL contribute to different traits, rather than a question of discrete sets of QTL contributing to discrete sets of traits.

scholarly journals Variability of root traits in common bean genotypes at different levels of phosphorus supply and ontogenetic stages

2014 ◽  
Vol 38 (4) ◽  
pp. 1170-1180 ◽  
Author(s):  
Roberto dos Santos Trindade ◽  
Adelson Paulo Araújo
Keyword(s):  
Common Bean ◽  
Root Length ◽  
Root Traits ◽  
Growth Stages ◽  
Phenotypic Variance ◽  
Root Mass ◽  
Root Area ◽  
Ontogenetic Stages ◽  
Growth Habits ◽  
Selection Of

Selection of common bean (Phaseolus vulgaris L.) cultivars with enhanced root growth would be a strategy for increasing P uptake and grain yield in tropical soils, but the strong plasticity of root traits may compromise their inclusion in breeding programs. The aim of this study was to evaluate the magnitude of the genotypic variability of root traits in common bean plants at two ontogenetic stages and two soil P levels. Twenty-four common bean genotypes, comprising the four growth habits that exist in the species and two wild genotypes, were grown in 4 kg pots at two levels of applied P (20 and 80 mg kg-1) and harvested at the stages of pod setting and early pod filling. Root area and root length were measured by digital image analysis. Significant genotype × P level and genotype × harvest interactions in analysis of variance indicate that the genotypic variation of root traits depended on soil nutrient availability and the stage at which evaluation was made. Genotypes differed for taproot mass, basal and lateral root mass, root area and root length at both P levels and growth stages; differences in specific root area and length were small. Genotypes with growth habits II (upright indeterminate) and III (prostrate indeterminate) showed better adaptation to limited P supply than genotypes of groups I (determinate) and IV (indeterminate climbing). Between the two harvests, genotypes of groups II and III increased the mass of basal and lateral roots by 40 and 50 %, respectively, whereas genotypes of groups I and IV by only 7 and 19 %. Values of the genotypic coefficient of determination, which estimates the proportion of phenotypic variance resulting from genetic effects, were higher at early pod filling than at pod setting. Correlations between shoot mass and root mass, which could indicate indirect selection of root systems via aboveground biomass, were higher at early pod filling than at pod setting. The results indicate that selection for root traits in common bean genotypes should preferentially be performed at the early pod-filling stage.

scholarly journals Estimation of variance components, genetic parameters and genetic trends for litter size of swines

2010 ◽  
Vol 39 (10) ◽  
pp. 2155-2159 ◽  
Author(s):  
Leandro Barbosa ◽  
Paulo Sávio Lopes ◽  
Adair José Regazzi ◽  
Robledo de Almeida Torres ◽  
Mário Luiz Santana Júnior ◽  
...  
Keyword(s):  
Litter Size ◽  
Variance Components ◽  
Genetic Parameters ◽  
Random Effect ◽  
Additive Model ◽  
Fixed Effect ◽  
Likelihood Method ◽  
Phenotypic Variance ◽  
Estimation Of Variance ◽  
Genetic Trends

Records of Large White breed animals were used to estimate variance components, genetic parameters and trends for the character total number of born piglets (TNBP) as measure of litter size. For obtaining variance components and genetic parameters, it was used the Restricted Maximum Likelihood Method using MTDFREML software. Two mixed models (additive and repeatability) were evaluated. The additive model contained fixed effect of the contemporary group and the following random effects: direct additive genetic and residual effect for the first parturition. Repeatability model had the same effects of the additive model plus parturition order fixed effect and non-correlated animal permanent environment random effect for the second, third and forth parturition. Direct additive heritability estimates for TNBP were 0.15 and 0.20 for the additive and repeatability models, respectively. The estimate of the ration among variance of the non-correlated effect of animal permanent environment effect and the phenotypic variance, expressed as total variance proportion (c2) was 0.09. The estimates of yearly genetic trends obtained in the additive and repeatability models have similar behaviors (0.02 piglets/sow/year).

scholarly journals Quantitative Trait Loci Affecting Survival and Fertility-Related Traits in Caenorhabditis elegans Show Genotype-Environment Interactions, Pleiotropy and Epistasis

Genetics ◽  
1999 ◽  
Vol 153 (3) ◽  
pp. 1233-1243 ◽  
Author(s):  
David R Shook ◽  
Thomas E Johnson
Keyword(s):  
Caenorhabditis Elegans ◽  
Quantitative Trait Loci ◽  
Population Growth ◽  
Quantitative Trait ◽  
Age Of Onset ◽  
Inbred Strains ◽  
Interval Mapping ◽  
Phenotypic Variance ◽  
Epistatic Interactions ◽  
Trait Loci

Abstract We have identified, using composite interval mapping, quantitative trait loci (QTL) affecting a variety of life history traits (LHTs) in the nematode Caenorhabditis elegans. Using recombinant inbred strains assayed on the surface of agar plates, we found QTL for survival, early fertility, age of onset of sexual maturity, and population growth rate. There was no overall correlation between survival on solid media and previous measures of survival in liquid media. Of the four survival QTL found in these two environments, two have genotype-environment interactions (GEIs). Epistatic interactions between markers were detected for four traits. A multiple regression approach was used to determine which single markers and epistatic interactions best explained the phenotypic variance for each trait. The amount of phenotypic variance accounted for by genetic effects ranged from 13% (for internal hatching) to 46% (for population growth). Epistatic effects accounted for 9–11% of the phenotypic variance for three traits. Two regions containing QTL that affected more than one fertility-related trait were found. This study serves as an example of the power of QTL mapping for dissecting the genetic architecture of a suite of LHTs and indicates the potential importance of environment and GEIs in the evolution of this architecture.

A NEW STRATEGY FOR THE SELECTION OF DOPAMINE AGONISTS AND ANTAGONISTS

1979 ◽  
pp. 1236-1238
Author(s):  
J.R. Boissier ◽  
F. Labrie ◽  
M. Beaulieu ◽  
T. Di Paolo ◽  
C. Oberlander ◽  
...  
Keyword(s):  
Dopamine Agonists ◽  
Dopamine Agonists And Antagonists ◽  
New Strategy ◽  
Selection Of

scholarly journals New strategy for efficient selection of dendritic cell-tumor hybrids and clonal heterogeneity of resulting hybrids

2004 ◽  
Vol 3 (11) ◽  
pp. 1145-1151 ◽  
Author(s):  
Hiroyuki Matsue ◽  
Keiko Matsue ◽  
Dale Edelbaum ◽  
Michael Walters ◽  
Akimichi Morita ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Cell Tumor ◽  
Clonal Heterogeneity ◽  
New Strategy ◽  
Efficient Selection ◽  
Selection Of

Using blup to estimate responses est a sheep flock selected for litter size

1993 ◽  
Vol 1993 ◽  
pp. 105-105
Author(s):  
G.E. Pollott
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Phenotypic Variance ◽  
Sheep Flock ◽  
Sheep Population ◽  
Important Contributor ◽  
Selection Experiments ◽  
Genetic Trends

The reproductive performance of ewes is an important contributor to flock profitability in many different situations. Although the heritability of reproductive traits is low there is often enough phenotypic variance to make a consideration of selection a possibility for improvement in litter size. Genetic trends in selection experiments have traditionally been monitored using a control flock which should be kept as an unseletced group. The recent availability of user friedly BLUP programs have added an extra method for estimating genetic trends. This paper reports the use of BLUP to estimate the genetic trends in a sheep population selected for litter size.

scholarly journals Quantifying the Genetic Basis of Marfan Syndrome Clinical Variability

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 574
Author(s):  
Thomas Grange ◽  
Mélodie Aubart ◽  
Maud Langeois ◽  
Louise Benarroch ◽  
Pauline Arnaud ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Clinical Features ◽  
Familial Aggregation ◽  
Phenotypic Variability ◽  
Connective Tissue Disorder ◽  
Clinical Feature ◽  
Phenotypic Variance ◽  
Genetic Modifiers ◽  
Clinical Variability ◽  
New Strategy

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder with considerable inter- and intra-familial clinical variability. The contribution of inherited modifiers to variability has not been quantified. We analyzed the distribution of 23 clinical features in 1306 well-phenotyped MFS patients carrying FBN1 mutations. We found strong correlations between features within the same system (i.e., ophthalmology vs. skeletal vs. cardiovascular) suggesting common underlying determinants, while features belonging to different systems were largely uncorrelated. We adapted a classical quantitative genetics model to estimate the heritability of each clinical feature from phenotypic correlations between relatives. Most clinical features showed strong familial aggregation and high heritability. We found a significant contribution by the major locus on the phenotypic variance only for ectopia lentis using a new strategy. Finally, we found evidence for the “Carter effect” in the MFS cardiovascular phenotype, which supports a polygenic model for MFS cardiovascular variability and indicates additional risk for children of MFS mothers with an aortic event. Our results demonstrate that an important part of the phenotypic variability in MFS is under the control of inherited modifiers, widely shared between features within the same system, but not among different systems. Further research must be performed to identify genetic modifiers of MFS severity.

Reproductive attributes of local pig (Votho) of Nagaland, India

2016 ◽  
Author(s):  
N. Savino ◽  
Z. Chusi ◽  
A. Dhali ◽  
P. Perumal
Keyword(s):  
Mortality Rate ◽  
Litter Size ◽  
Field Survey ◽  
Gestation Length ◽  
Reproductive Parameters ◽  
Litter Weight ◽  
Significant Difference ◽  
Size At Birth ◽  
Selection Of ◽  
Age At First Farrowing

The present study was conducted to measure the reproductive attributes of Naga local pigs (Votho) in Kohima, Peren and Phek district of Nagaland. The reproductive parameters were measured through field survey and reproductive records of owner. The reproductive parameters such as age at first fertile service (AFFS), age at first farrowing (AFF), gestation length, farrowing interval, litter size at birth, litter size at weaning, litter weight at birth, litter weight at weaning, mortality rate and stillbirth rate were measured. The result revealed that there was a significant difference among the different districts of Nagaland in AFFS, AFF and litter weight at birth. Parameters such as AFFS, AFF and litter weight at birth were significantly higher and gestation length, farrowing interval, litter size at weaning, litter weight at birth, litter weight at weaning were non-significantly higher in Kohima than in Peren and Phek District. Similarly, parameters such as litter size at birth, mortality rate were non-significantly higher in Peren district and stillbirth was non- significantly higher in Phek district than other districts of Nagaland. These reproductive attributes analyses may be useful in selection of breeding stock for future parents and select the place for breeding programme for indigenous local Naga pigs.

Multitrait and repeatability estimates of random effects on litter size in sheep

2002 ◽  
Vol 74 (2) ◽  
pp. 209-216 ◽  
Author(s):  
C. Hagger
Keyword(s):  
Litter Size ◽  
Random Effects ◽  
Genetic Gain ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Parameter Estimates ◽  
Data Sets ◽  
Phenotypic Variance ◽  
The Third ◽  
Meat Sheep

AbstractFive data sets with records of first, second and third lambings of the White Alpine sheep (WAS1, WAS2), the Brown-Headed Meat sheep (BFS), the Black-Brown Mountain sheep (SBS) and the Valais Black-Nose sheep (SNS) of Switzerland were used to estimate phenotypic and genetic parameters for litter size using a multitrait and a repeatability model by the REML method. The sets contained litter information from 26 274, 25 165, 18 913, 14 953 and 21 726 ewes, respectively. Average numbers of litters per ewe were between 2·09 and 2·31. Average litter sizes at birth were between 1·36 and 1·57 lambs in first, between 1·52 and 1·75 in second and, between 1·56 and 1·86 in third parities. Multitrait estimates of heritability for size of first litters were 0·164, 0·157, 0·117, 0·223 and 0·116 for the WAS1, WAS2, BFS, SBS and SNS data, respectively. The corresponding estimates were 0·176, 0·165, 0·140, 0·208 and 0·134 for second and, 0·141, 0·155, 0·121, 0·145 and 0·107 for third litters. The systematic increase in phenotypic variances from first to third litter within data sets favoured the multivariate over the repeatability approach. Genetic correlations between size of the first three litters were, with one exception, above 0·927. Random flock ✕ year and sire of litter effects contributed between 2·2% and 13·2% and between 0·7% and 4·7% to the phenotypic variance of the traits, respectively. Residuals contributed between 70·6% and 84·2% to this parameter, estimates for the third litter were always highest. Heritability estimates from the repeatability model were smaller than the smallest multivariate estimates. Expected genetic gain in litter size from selection on the multitrait model was equal to the achieved response from the repeatability approach.

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