title: Quantitative system drift compensates for altered maternal inputs to the gap gene network of the scuttle fly Megaselia abdita.
abstract: The segmentation gene network in insects can produce equivalent phenotypic outputs despite differences in upstream regulatory inputs between species. We investigate the mechanistic basis of this phenomenon through a systems-level analysis of the gap gene network in the scuttle fly Megaselia abdita (Phoridae). It combines quantification of gene expression at high spatio-temporal resolution with systematic knock-downs by RNA interference (RNAi). Initiation and dynamics of gap gene expression differ markedly between M. abdita and Drosophila melanogaster, while the output of the system converges to equivalent patterns at the end of the blastoderm stage. Although the qualitative structure of the gap gene network is conserved, there are differences in the strength of regulatory interactions between species. We term such network rewiring 'quantitative system drift'. It provides a mechanistic explanation for the developmental hourglass model in the dipteran lineage. Quantitative system drift is likely to be a widespread mechanism for developmental evolution.
authors.affiliation: European Molecular Biology Laboratory, CRG Systems Biology Research Unit, Centre for Genomic Regulation, Barcelona, Spain.
authors.forename: Karl R
authors.initials: KR
authors.lastname: Wotton
authors.affiliation: European Molecular Biology Laboratory, CRG Systems Biology Research Unit, Centre for Genomic Regulation, Barcelona, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Jiménez-Guri
authors.affiliation: European Molecular Biology Laboratory, CRG Systems Biology Research Unit, Centre for Genomic Regulation, Barcelona, Spain.
authors.forename: Anton
authors.initials: A
authors.lastname: Crombach
authors.affiliation: European Molecular Biology Laboratory, CRG Systems Biology Research Unit, Centre for Genomic Regulation, Barcelona, Spain.
authors.forename: Hilde
authors.initials: H
authors.lastname: Janssens
authors.affiliation: European Molecular Biology Laboratory, CRG Systems Biology Research Unit, Centre for Genomic Regulation, Barcelona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Alcaine-Colet
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, United States.
authors.forename: Steffen
authors.initials: S
authors.lastname: Lemke
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, United States.
authors.forename: Urs
authors.initials: U
authors.lastname: Schmidt-Ott
authors.affiliation: European Molecular Biology Laboratory, CRG Systems Biology Research Unit, Centre for Genomic Regulation, Barcelona, Spain.
authors.forename: Johannes
authors.initials: J
authors.lastname: Jaeger
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics; D030541:Databases, Genetic; D004175:Diptera / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000378:metabolism; D019143:Evolution, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D017344:Genes, Insect; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D012333:RNA, Messenger
keywords: D. melanogaster; Megaselia abdita; RNA interference; data quantification; developmental biology; developmental system drift; evolutionary biology; evolutionary developmental biology (evo-devo); gap gene network; genomics; stem cells