Int. J. Dev. Biol. 53: 189 - 190 (2009)
doi: 10.1387/ijdb.092909sk
© UPV/EHU Press

Preface to the "Epigenetics & Development" Special Issue

Saadi Khochbin and Stefan Nonchev

Institut Albert Bonniot, INSERM U823, University Joseph Fourier, Grenoble, France

ABSTRACT In animals and plants, development is controlled by the orchestrated interaction of gene networks responsible for shaping cell differentiation and morphogenesis. The identification of major families of developmental genes in the 1980s and 1990s started shedding light on the components of signalling pathways and their interplay with transcription factors to impose specific developmental programs. The plethora of phenotypes generated by transgenics technology in various organisms helped to decipher several levels of complexity and suggested that gene function might be intimately linked to chromatin accessibility and alteration at key developmental loci. Over the last decade, an explosion of data from the genome-wide exploration of regulatory regions has indicated that epigenetic modifications of chromatin structure play an essential role in the regulation of gene expression. It is now conceivable that developmental strategies largely rely on epigenetic mechanisms to establish and stabilize appropriate gene expression patterns. While cell differentiation uses a genetic program to generate a specific profile of gene activity, the setting of these expression patterns involves genome-encoded mechanisms which functionally mark genomic loci. In a differentiating cell, a selected group of genes functions in a highly tuned manner, while large parts of the genome remain silent. During this process called “reprogramming”, a differentiating cell is set to execute a program, which can be considered as epigenetic since it governs the function of the genome in a heritable manner without affecting the DNA sequence. Here the real epigenetic world starts, since the establishment and maintenance of epigenetic marks is reversible and heritable and responds to a large spectrum of external stimuli...


epigenetics, gene network, reprograming

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