The objective of the current study was to identify QTL conferring resistance to Marek's disease (MD) in commercial layer chickens. To generate the resource population, 2 partially inbred lines that differed in MD-caused mortality were intermated to produce 5 backcross families. Vaccinated chicks were challenged with very virulent plus (vv+) MD virus strain 648A at 6 d and monitored for MD sympt...

BACKGROUND Genomic selection is particularly beneficial for difficult or expensive to measure traits. Since multi-trait selection is an important tool to deal with such cases, an important question is what the added value is of multi-trait genomic selection. METHODS The simulated dataset, including a quantitative and binary trait, was analyzed with four univariate and bivariate linear models ...

We evaluated the potential of the best linear unbiased predictor (BLUP) along with the relationship coefficient for predicting the performance of untested maize single-cross hybrids. Ninety S(0:2) progenies arising from three single-cross hybrids were used. The 90 progenies were genotyped with 25 microsatellite markers, with nine markers linked to quantitative trait loci for grain yield. Based ...

Standard quantitative trait loci (QTL) mapping techniques commonly assume that the trait is both fully observed and normally distributed. When considering survival or age-at-onset traits these assumptions are often incorrect. Methods have been developed to map QTL for survival traits; however, they are both computationally intensive and not available in standard genome analysis software package...

Principal components analysis has been employed in gene expression studies to correct for population substructure and batch and environmental effects. This method typically involves the removal of variation contained in as many as 50 principal components (PCs), which can constitute a large proportion of total variation present in the data. Each PC, however, can detect many sources of variation,...

Recombinant inbred populations of many plant species exhibit more heterozygosity than expected under the Mendelian model of segregation. This segregation distortion causes the overestimation of recombination frequencies and consequent genetic map expansion. Here we build upon existing genetic models of differential zygotic viability to model a heterozygote fitness term and calculate expected ge...

Mutation generates the heritable variation that genetic drift and natural selection shape. In classical quantitative genetic models, drift is a function of the effective population size and acts uniformly across traits, whereas mutation and selection act trait-specifically. We identified thousands of quantitative trait loci (QTLs) influencing transcript abundance traits in a cross of two Caenor...

In association mapping, haplotype-based methods are generally regarded to provide higher power and increased precision than methods based on single markers. For haplotype-based association mapping most studies use a fixed haplotype effect in the model. However, an increase in haplotype length raises the number of parameters in the model, resulting in low accuracy of the estimates especially for...

There are many theoretical approaches for studying the evolution of parental care and parent–offspring interactions (Chapters 2, 7, 9, and 16; Mock and Parker 1997), but here I focus on theory developed in the field of quantitative genetics. The reasons for this are twofold; first, they allow tractable dynamic models for phenotypes determined by multiple genes and the environment. Second, theor...

PURPOSE To provide predictive cosolvency models, the Abraham solvation parameters of solutes and the solvent coefficients were combined with the Jouyban-Acree and the log-linear models. These models require two and one solubility data points to predict the solubility of drugs in water-cosolvent mixtures. Ab initio prediction methods also were employed and the results were discussed. METHOD Th...