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Mixed Effects Structural Equation Models and Phenotypic Causal Networks

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First Online:
Part of the Methods in Molecular Biology book series (MIMB, volume 1019)

Abstract

Complex networks with causal relationships among variables are pervasive in biology. Their study, however, requires special modeling approaches. Structural equation models (SEM) allow the representation of causal mechanisms among phenotypic traits and inferring the magnitude of causal relationships. This information is important not only in understanding how variables relate to each other in a biological system, but also to predict how this system reacts under external interventions which are common in fields related to health and food production. Nevertheless, fitting a SEM requires defining a priori the causal structure among traits, which is the qualitative information that describes how traits are causally related to each other. Here, we present directions for the applications of SEM to investigate a system of phenotypic traits after searching for causal structures among them. The search may be performed under confounding effects exerted by genetic correlations.

Key words

Causal structure search Inductive causation algorithm Multiple-trait models Phenotype networks Structural equation models 
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Notes

Acknowledgments

The authors thank Gustavo de los Campos for his contribution on the development of the function gibbsREC. This work was supported by the Agriculture and Food Research Initiative Competitive Grant no. 2011-67015-30219 from the USDA National Institute of Food and Agriculture.

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Copyright information

© Springer Science+Business Media, LLC 2013

Authors and Affiliations

  1. 1.Department of Animal ScienceUniversity of Wisconsin-MadisonMadisonUSA
  2. 2.Department of Biostatistics & Medical InformaticsUniversity of Wisconsin-MadisonMadisonUSA

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