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Weighted single-step genomic BLUP: an iterative approach for accurate calculation of GEBV and GWAS

Tuesday, August 19, 2014
Posters (The Westin Bayshore)
Xinyue Zhang , University of Georgia, Athens, GA
Daniela A. L. Lourenco , University of Georgia, Athens, GA
Ignacy Misztal , University of Georgia, Athens, GA
Ignacio Aguilar , INIA, Las Brujas, Uruguay
Andres Legarra , INRA, UMR 1388 GenPhySE, Castanet-Tolosan, France
Abstract Text: Three different procedures were implemented to calculate weights for a genomic relationship matrix to restrict the shrinkage along iterations of weighted single-step genomic BLUP (WssGBLUP).  The procedures as well as BayesC were tested with 3 simulated data sets. Prediction accuracy for WssGBLUP improved at 2nd or 3rd iteration by updating only the top number of SNP equal to 1 × or 3 × the number of QTL; accuracy increased after 3rd iteration and remained stable by using weights proportional to 2pi(1- pi)ui2+ constant. Except in the 5 QTL scenario, accuracies with all WssGBLUP procedures were higher than with BayesC. Noise in Manhattan plots was small with 5 and 100 QTL but large with 500 QTL.

Keywords: GWAS, WssGBLUP, BayesC