Mechanisms of Development While traditional breeding schemes relied on progeny phenotyping and subsequent sire evaluation, the genetic value of individuals can now be accurately inferred based on genotype information only i. The blue line is a linear regression line with slope 3. Dividing the mapping population into reference and validation population overcomes this issue [93], albeit at the cost of loosing power to detect association. Fitting a linear regression model yielded an average substitution effect of Thus we consider the polymorphism as a candidate quantitative trait nucleotide QTN position.

Twelve genomic regions were highly significantly associated. The aim of the present study was to gain insights into the genetic architecture of a special aspect of skin pigmentation and to provide the basis for more efficient selection for animals that are less susceptible to serious eye diseases. However, a large fraction of the genetic variation results from chromosomes without identified QTL. Thus we consider the polymorphism as a candidate quantitative trait nucleotide QTN position. Large-scale genotyping of a substantial number of individuals provides comprehensive insights into the genetic variability between as well as within populations. The estimate of the proportion of phenotypic variance explained by a particular chromosome is displayed as a function of the physical chromosome length in Mb units.

The proportion of trait variance explained by an average QTL is very small.

dissertation hubert pausch

Furthermore, causal variants affecting regulatory elements may be located very distantly from the regulated gene, complicating theirs identification considerably [1].

An important prerequisite for unbiased QTL mapping based on linkage disequilibrium LD is homogeneity of the mapping population [11]. The solid line represents the population mean, the dotted lines indicate one standard deviation of the EBV. Sample size required to identify a QTL for traits with different hjbert.

Qianqian Zhang: Towards Cattle Precision Breeding Using Next Generation Sequencing

Development Cambridge, England Stillbirth is recorded as categorical trait alive or not 48 hours post partum. The heatmap displays the pairwise didsertation disequilibrium. Barendse W The effect of measurement error of phenotypes on genome wide association studies. Polymorphism analysis of genes in a 3. The most significant SNP on chromosome 14 exhibit an allele substitution effect of However, the approach of partitioning the genetic variation by fitting the effects of all chromosomes separately [20] used in the present thesis has not been applied hitherto in cattle populations, precluding a meaningful comparison with other traits.


(PDF) Genome-wide analysis of complex traits in cattle | Hubert Pausch –

Annals of the New York Academy of Sciences Holmberg M, Andersson-Eklund L Quantitative trait loci affecting fertility and calving traits in Swedish dairy cattle. Variants of this gene may predispose to lactating SNTs, which are particularly undesirable. Assessing phenotypes for ACOP in the genotyped male animals might enable to quantify the extent of non-additive effects. On the other hand it seems likely that the QTL accounts for a small fraction of the genetic variation only, requiring larger sample sizes for its huberrt.

The distribution of loci with large effects is a major issue for the the appropriate model selection for genomic prediction in cattle populations.

Qianqian Zhang: Towards Cattle Precision Breeding Using Next Generation Sequencing

Journal of Human Evolution The methods used in exploiting hubet use of whole genome sequence variants can be useful in studying other livestock species. However, since the twelve identified QTL regions account for As EBVs for paternal calving traits mainly reflect fetal growth, birth weight would be a more precise phenotype to identify QTL for fetal growth. This dual purpose selection is likely to act on the two QTL identified in our study. Although the twelve identified QTL regions already account for Nevertheless, daughter yield deviations DYDs were claimed to be the phenotypes of choice for QTL studies in pedigreed populations [9],[10].


Re- sequencing a small number of key animals enables to assess a large fraction of the global genomic variation of livestock populations [2],[3].

I also want to mention Pasch Hoffmann for her help in administrative matters. We discuss the various implications dissertatlon this observation The linear relationship between chromosome length and its contribution to the genetic variation seems to be more prominent in production traits [18],[19].

However, a prominent calving ease QTL in the Holstein breed dissetation chromosome 18 [2] could not be detected in the present study or is not segregating in the Fleckvieh breed.

dissertation hubert pausch

Nature Reviews Genetics 6: Although incorrectly placed SNPs are particularly obstructive for haplotype-based analysis such as homozygosity mapping and the identification of selective sweeps [90], the position of significantly associated SNPs should also be validated in GWAS to avoid misinterpretation of significant associations [91]. Calving ease is a major breeding objective in cattle populations as calving difficulties dystocia are often accompanied with calf losses and thus substantially compromise animal and economical welfare.

Furthermore, dystocia seriously compromises milk production and reproductive performance of pertinently affected cows [55],[56],[57],[58]. Assessment of the genomic variation in a cattle population based on low-coverage re-sequencing.

The inflation of significant association signals most likely results from relatedness of animals leading to massively structured population. Click here to sign up.

dissertation hubert pausch