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Peter Sørensen

A two step Bayesian approach for genomic prediction of breeding values

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisKonferenceartikelForskningpeer review

Background: In genomic models that assign an individual variance to each marker, the contribution of one marker to the posterior distribution of the marker variance is only one degree of freedom (df), which introduces many
variance parameters with only little information per variance parameter. A better alternative could be to form clusters of markers with similar effects where markers in a cluster have a common variance. Therefore, the
influence of each marker group of size p on the posterior distribution of the marker variances will be p df.
Methods: The simulated data from the 15th QTL-MAS workshop were analyzed such that SNP markers were ranked based on their effects and markers with similar estimated effects were grouped together. In step 1, all markers with
minor allele frequency more than 0.01 were included in a SNP-BLUP prediction model. In step 2, markers were ranked based on their estimated variance on the trait in step 1 and each 150 markers were assigned to one group with a common variance. In further analyses, subsets of 1500 and 450 markers with largest effects in step 2 were kept in the prediction model.
Results: Grouping markers outperformed SNP-BLUP model in terms of accuracy of predicted breeding values. However, the accuracies of predicted breeding values were lower than Bayesian methods with marker specific variances.
Conclusions: Grouping markers is less flexible than allowing each marker to have a specific marker variance but, by grouping, the power to estimate marker variances increases. A prior knowledge of the genetic architecture of
the trait is necessary for clustering markers and appropriate prior parameterization
TidsskriftBMC Proceedings
Nummer(Suppl 2):S12
Antal sider5
StatusUdgivet - 21 maj 2012
Begivenhed15th European workshop on QTL mapping and assisted selection (QTLMAS) - Rennes, Frankrig
Varighed: 19 maj 201120 maj 2011
Konferencens nummer: 15TH


Workshop15th European workshop on QTL mapping and assisted selection (QTLMAS)

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