title: Spatiotemporal network motif reveals the biological traits of developmental gene regulatory networks in Drosophila melanogaster.
abstract: BACKGROUND
  Network motifs provided a "conceptual tool" for understanding the functional principles of biological networks, but such motifs have primarily been used to consider static network structures. Static networks, however, cannot be used to reveal time- and region-specific traits of biological systems. To overcome this limitation, we proposed the concept of a "spatiotemporal network motif," a spatiotemporal sequence of network motifs of sub-networks which are active only at specific time points and body parts.
  
  
  RESULTS
  On the basis of this concept, we analyzed the developmental gene regulatory network of the Drosophila melanogaster embryo. We identified spatiotemporal network motifs and investigated their distribution pattern in time and space. As a result, we found how key developmental processes are temporally and spatially regulated by the gene network. In particular, we found that nested feedback loops appeared frequently throughout the entire developmental process. From mathematical simulations, we found that mutual inhibition in the nested feedback loops contributes to the formation of spatial expression patterns.
  
  
  CONCLUSIONS
  Taken together, the proposed concept and the simulations can be used to unravel the design principle of developmental gene regulatory networks.
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors.forename: Man-Sun
authors.initials: MS
authors.lastname: Kim
authors.forename: Jeong-Rae
authors.initials: JR
authors.lastname: Kim
authors.forename: Dongsan
authors.initials: D
authors.lastname: Kim
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Lander
authors.forename: Kwang-Hyun
authors.initials: KH
authors.lastname: Cho
mesh_terms: D000818:Animals; D019295:Computational Biology / Q000379:methods*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development*; D053263:Gene Regulatory Networks; D017344:Genes, Insect / Q000235:genetics; D008957:Models, Genetic; D010641:Phenotype; D062211:Spatio-Temporal Analysis