Cell state switching factors and dynamical patterning modules: complementary mediators of plasticity in development and evolution
Autor: | Ramray Bhat, Nadejda V. Mezentseva, Stuart A. Newman |
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Rok vydání: | 2009 |
Předmět: |
Limb Buds
Cellular differentiation Morphogenesis Adaptation Biological Embryonic Development Chick Embryo Biology General Biochemistry Genetics and Molecular Biology Cell polarity Cell Adhesion Animals Gene Regulatory Networks Transcription factor Body Patterning Regulation of gene expression Phenotypic plasticity Cell Polarity Gene Expression Regulation Developmental Cell Differentiation General Medicine Biological Evolution Cell biology Developmental plasticity Adaptation General Agricultural and Biological Sciences Signal Transduction Transcription Factors |
Zdroj: | Journal of Biosciences. |
ISSN: | 0973-7138 0250-5991 |
Popis: | Ancient metazoan organisms arose from unicellular eukaryotes that had billions of years of genetic evolution behind them. The transcription factor networks present in single-celled ancestors at the origin of the Metazoa (multicellular animals) were already capable of mediating the switching of the unicellular phenotype among alternative states of gene activity in response to environmental conditions. Cell differentiation, therefore, had its roots in phenotypic plasticity, with the ancient regulatory proteins acquiring new targets over time and evolving into the “developmental transcription factors” (DTFs) of the “developmental-genetic toolkit.” In contrast, the emergence of pattern formation and morphogenesis in the Metazoa had a different trajectory. Aggregation of unicellular metazoan ancestors changed the organisms’ spatial scale, leading to the first “dynamical patterning module” (DPM): cell-cell adhesion. Following this, other DPMs (defined as physical forces and processes pertinent to the scale of the aggregates mobilized by a set of toolkit gene products distinct from the DTFs), transformed simple cell aggregates into hollow, multilayered, segmented, differentiated and additional complex structures, with minimal evolution of constituent genes. Like cell differentiation, therefore, metazoan morphologies also originated from plastic responses of cells and tissues. Here we describe examples of DTFs and most of the important DPMs, discussing their complementary roles in the evolution of developmental mechanisms. We also provide recently characterized examples of DTFs in cell type switching and DPMs in morphogenesis of avian limb bud mesenchyme, an embryo-derived tissue that retains a high degree of developmental plasticity. |
Databáze: | OpenAIRE |
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