title: Functional evolution of a morphogenetic gradient.
abstract: Bone Morphogenetic Proteins (BMPs) pattern the dorsal-ventral axis of bilaterian embryos; however, their roles in the evolution of body plan are largely unknown. We examined their functional evolution in fly embryos. BMP signaling specifies two extraembryonic tissues, the serosa and amnion, in basal-branching flies such asMegaselia abdita, but only one, the amnioserosa, inDrosophila melanogaster. The BMP signaling dynamics are similar in both species until the beginning of gastrulation, when BMP signaling broadens and intensifies at the edge of the germ rudiment inMegaselia, while remaining static inDrosophila. Here we show that the differences in gradient dynamics and tissue specification result from evolutionary changes in the gene regulatory network that controls the activity of a positive feedback circuit on BMP signaling, involving thetumor necrosis factor alphahomologeiger. These data illustrate an evolutionary mechanism by which spatiotemporal changes in morphogen gradients can guide tissue complexity.
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, United States.
authors.forename: Chun Wai
authors.initials: CW
authors.lastname: Kwan
authors.affiliation: Department of Ecology and Evolution, University of Chicago, Chicago, United States.
authors.forename: Jackie
authors.initials: J
authors.lastname: Gavin-Smyth
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, United States.|Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, United States.
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Ferguson
authors.affiliation: Department of Organismal Biology and Anatomy, University of Chicago, Chicago, United States.
authors.forename: Urs
authors.identifier: http://orcid.org/0000-0002-1351-9472
authors.initials: U
authors.lastname: Schmidt-Ott
mesh_terms: D000818:Animals; D019521:Body Patterning; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D004175:Diptera / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D007814:Larva / Q000254:growth & development
chemical_list: D019485:Bone Morphogenetic Proteins
keywords: Bone Morphogenetic Protein; D. melanogaster; Megaselia abdita; amnion; developmental biology; eiger; positive feedback; serosa; stem cells