PMID- 30356716 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20220410 IS - 1664-8021 (Print) IS - 1664-8021 (Electronic) IS - 1664-8021 (Linking) VI - 9 DP - 2018 TI - Including Phenotypic Causal Networks in Genome-Wide Association Studies Using Mixed Effects Structural Equation Models. PG - 455 LID - 10.3389/fgene.2018.00455 [doi] LID - 455 AB - Network based statistical models accounting for putative causal relationships among multiple phenotypes can be used to infer single-nucleotide polymorphism (SNP) effect which transmitting through a given causal path in genome-wide association studies (GWAS). In GWAS with multiple phenotypes, reconstructing underlying causal structures among traits and SNPs using a single statistical framework is essential for understanding the entirety of genotype-phenotype maps. A structural equation model (SEM) can be used for such purposes. We applied SEM to GWAS (SEM-GWAS) in chickens, taking into account putative causal relationships among breast meat (BM), body weight (BW), hen-house production (HHP), and SNPs. We assessed the performance of SEM-GWAS by comparing the model results with those obtained from traditional multi-trait association analyses (MTM-GWAS). Three different putative causal path diagrams were inferred from highest posterior density (HPD) intervals of 0.75, 0.85, and 0.95 using the inductive causation algorithm. A positive path coefficient was estimated for BM --> BW, and negative values were obtained for BM --> HHP and BW --> HHP in all implemented scenarios. Further, the application of SEM-GWAS enabled the decomposition of SNP effects into direct, indirect, and total effects, identifying whether a SNP effect is acting directly or indirectly on a given trait. In contrast, MTM-GWAS only captured overall genetic effects on traits, which is equivalent to combining the direct and indirect SNP effects from SEM-GWAS. Although MTM-GWAS and SEM-GWAS use the similar probabilistic models, we provide evidence that SEM-GWAS captures complex relationships in terms of causal meaning and mediation and delivers a more comprehensive understanding of SNP effects compared to MTM-GWAS. Our results showed that SEM-GWAS provides important insight regarding the mechanism by which identified SNPs control traits by partitioning them into direct, indirect, and total SNP effects. FAU - Momen, Mehdi AU - Momen M AD - Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran. FAU - Ayatollahi Mehrgardi, Ahmad AU - Ayatollahi Mehrgardi A AD - Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran. FAU - Amiri Roudbar, Mahmoud AU - Amiri Roudbar M AD - Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran. FAU - Kranis, Andreas AU - Kranis A AD - Roslin Institute, University of Edinburgh, Midlothian, United Kingdom. FAU - Mercuri Pinto, Renan AU - Mercuri Pinto R AD - Department of Exact Sciences, University of Sao Paulo-Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, Brazil. AD - Department of Animal Sciences, University of Wisconsin, Madison, WI, United States. FAU - Valente, Bruno D AU - Valente BD AD - Department of Animal Sciences, University of Wisconsin, Madison, WI, United States. FAU - Morota, Gota AU - Morota G AD - Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States. FAU - Rosa, Guilherme J M AU - Rosa GJM AD - Department of Animal Sciences, University of Wisconsin, Madison, WI, United States. AD - Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, United States. FAU - Gianola, Daniel AU - Gianola D AD - Department of Animal Sciences, University of Wisconsin, Madison, WI, United States. AD - Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, United States. AD - Department of Dairy Science, University of Wisconsin, Madison, WI, United States. LA - eng PT - Journal Article DEP - 20181009 PL - Switzerland TA - Front Genet JT - Frontiers in genetics JID - 101560621 PMC - PMC6189326 OTO - NOTNLM OT - GWAS OT - SEM OT - SNP effect OT - causal structure OT - multiple traits OT - path analysis EDAT- 2018/10/26 06:00 MHDA- 2018/10/26 06:01 PMCR- 2018/10/09 CRDT- 2018/10/26 06:00 PHST- 2018/06/21 00:00 [received] PHST- 2018/09/18 00:00 [accepted] PHST- 2018/10/26 06:00 [entrez] PHST- 2018/10/26 06:00 [pubmed] PHST- 2018/10/26 06:01 [medline] PHST- 2018/10/09 00:00 [pmc-release] AID - 10.3389/fgene.2018.00455 [doi] PST - epublish SO - Front Genet. 2018 Oct 9;9:455. doi: 10.3389/fgene.2018.00455. eCollection 2018.