Enriched partial correlations in genome-wide gene expression profiles of hybrids (A. thaliana): a systems biological approach towards the molecular basis of heterosis.
Heterosis is a well-known phenomenon but the underlying molecular mechanisms are not yet established. To contribute to the understanding of heterosis at the molecular level, we analyzed genome-wide gene expression profile data of Arabidopsis thaliana in a systems biological approach. We used partial correlations to estimate the global interaction structure of regulatory networks. Our hypothesis states that heterosis comes with an increased number of partial correlations which we interpret as increased numbers of regulatory interactions leading to enlarged adaptability of the hybrids. This hypothesis is true for mid-parent heterosis for our dataset of gene expression in two homozygous parental lines and their reciprocal crosses. For the case of best-parent heterosis just one hybrid is significant regarding our hypothesis based on a resampling analysis. Summarizing, both metabolome and gene expression level of our illustrative dataset support our proposal of a systems biological approach towards a molecular basis of heterosis.
Andorf
Sandra
S
Research Institute for the Biology of Farm Animals (FBN), Wilhelm-Stahl Allee 2, 18196 Dummerstorf, Germany.
Selbig
Joachim
J
Altmann
Thomas
T
Poos
Kathrin
K
Witucka-Wall
Hanna
H
Repsilber
Dirk
D
D017360:Arabidopsis / Q000235:genetics*; D020869:Gene Expression Profiling; D018745:Genome, Plant; D006823:Hybrid Vigor / Q000235:genetics*; D006824:Hybridization, Genetic; D049490:Systems Biology / Q000379:methods