Looking Beyond the Genes: The Interplay Between Signaling Pathways and Mechanics in the Shaping and Diversification of Epithelial Tissues.
The core of Evo-Devo lies in the intuition that the way tissues grow during embryonic development, the way they sustain their structure and function throughout lifetime, and the way they evolve are closely linked. Epithelial tissues are ubiquitous in metazoans, covering the gut and internal branched organs, as well as the skin and its derivatives (ie, teeth). Here, we discuss in vitro, in vivo, and in silico studies on epithelial tissues to illustrate the conserved, dynamical, and complex aspects of their development. We then explore the implications of the dynamical and nonlinear nature of development on the evolution of their size and shape at the phenotypic and genetic levels. In rare cases, when the interplay between signaling and mechanics is well understood at the cell level, it is becoming clear that the structure of development leads to covariation of characters, an integration which in turn provides some predictable structure to evolutionary changes. We suggest that such nonlinear systems are prone to genetic drift, cryptic genetic variation, and context-dependent mutational effects. We argue that experimental and theoretical studies at the cell level are critical to our understanding of the phenotypic and genetic evolution of epithelial tissues, including carcinomas.
University of Zürich, Institute of Physics, Zürich, Switzerland. Electronic address: surdy@physik.uzh.ch.
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Urdy
Univ Lyon, ENS Lyon, CNRS, Université Claude Bernard Lyon 1, Institut de Génomique Fonctionnelle de Lyon, UMR 5242, Lyon Cedex 07, France.
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Goudemand
Univ Lyon, ENS Lyon, CNRS, Université Claude Bernard Lyon 1, Laboratory of Biology and Modelling of the Cell, UMR 5239, INSERM U1210, Lyon Cedex 07, France.
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Pantalacci
D000818:Animals; D005075:Biological Evolution; D002874:Chromosome Mapping; D003198:Computer Simulation; D004848:Epithelium / Q000196:embryology / Q000254:growth & development / Q000502:physiology*; D005109:Extracellular Matrix / Q000502:physiology; D058685:Genetic Pleiotropy; D008322:Mammals; D009024:Morphogenesis; D009929:Organ Size / Q000502:physiology; D010641:Phenotype; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014070:Tooth / Q000196:embryology / Q000254:growth & development
Appendages; Branching; Cancer; Evo-Devo; Genetic architecture; Innovation; Integration; Mechanics; Morphodynamics; Morphogenesis; Simulation; Teeth; Tinkering; Wing