Genome wide association study and genomic selection are important approaches for genetic improvement of livestock. The objective of Xiaoping’s PhD project was to investigate the methods and models for GWAS and genomic prediction using markers of different densities. The results show conclusions are: 1) The power of QTL detection can be increased by increasing marker densities, and the Bayesian variable selection model together with the analysis of the QTL intensity profile outperforms the linear mixed model in refining QTL locations and presenting clear boundaries between different regions. 2) Close relationship between test and training animals is favorable while close relationship between animals within the training population is unfavorable for reliability of genomic predictions of candidate animals. In addition, the Bayesian mixture model performs better than GBLUP model especially when the relationship between training and test animals is weak. 3) Utilizing information of GWAS to separate SNP into two groups and allowing different variances to different SNP groups may be an alternative approach to improve reliability of genomic prediction. In addition, joint reference population of different breeds led to slight increase of prediction accuracy, compared with single-breed reference population.

The PhD degree was completed at the Department of Animal science and Technology, China Agriculture University, and Center for Genetics and Genomics, Department of Molecular Biology and Genetic, Aarhus University.

This résumé is prepared by the PhD student.

Time: Wednesday 26 November 2014 at 10:00
Place: Conference room 4, Department of Animal science and Technology, China Agriculture University, China
Title of dissertation: GWAS and genomic prediction based on markers of SNP-Chips and sequence data in dairy cattle populations
Contact information: Xiaoping Wu, e-mail: xiaoping.wu@mbg.au.dk, tel.: +45 91729856
Members of the assessment committee:
Professor Georg Thaller, Institut für Tierzucht und Tierhaltung, Christian-Albrechts-University Kiel, Germany
Professor Ning Yang, Department of Animal science and Technology, China Agriculture University, China
Professor Yan Fu, College of Animal Science, University of Zhejiang, China
Professor Jun Ren, College of Animal Science and Technology, Jiangxi Agriculture University, China
Professor Just Jensen (chair), Department of Molecular Biology and Genetics, Aarhus University
Main supervisor:
Professor Dongxiao Sun, Department of Animal science and Technology, China Agriculture University
Senior Scientist Guosheng Su, Department of Molecular Biology and Genetics, Aarhus University
Co-supervisor:
Professor Qin Zhang, Department of Animal science and Technology, China Agriculture University
Professor Mogens Sandø Lund, Department of Molecular Biology and Genetics, Aarhus University
Language: The PhD dissertation will be defended in English.

The defence is public.
The dissertation is available for reading at the Graduate School of Science and Technology/GSST, Ny Munkegade 120, building 1521, room 112, 8000 Aarhus C.