Sensing the Environment: Epigenetic Regulation of Gene Expression

Maria Cristina Vinci

doi:10.4172/2161-0398.s3-001

Abstract

The genomic era has just scratched the surface of the complex mechanisms responsible for bringing the organism phenotype into their being. In light of the recent discoveries, it is becoming clear that “other genetic” and environmental factors tightly interplay to provide information and instructions for the use of genetic material. Under this point of view, the DNA represents “the hardware”, the first ancestral genetic layer of cell information that is identical in all tissues of the individual; another layer of information differently distributed across the genome, continuously written, read and erased in response to both physical and social environmental signals, represents the cell “software”, the network connection with the changing world around us. Conrad H. Waddington (1942) termed this concept epigenetics to describe the hypothetical interaction among genes and their immediate surroundings during development and phenotype determination. Epigenetics is referred as the ensemble of functionally relevant modifications that regulate gene expression without altering the underlying DNA sequence. This article will examine the interaction between the genome, epigenome and environment with reference to how and when external signals affect long-term regulation of transcriptional programs.

Highlights

Are we the mere result of our genes? The decoding of the human genome at the turn of the millennium has opened the hope of discovering the most hidden mechanisms responsible for the organism phenotype
The language of epigenetic program is encoded by specific DNA and chromatin covalent modifications that regulate the accessibility of the DNA to the transcription machinery [3]
All organisms had to face changing environment, and adapting to it, to ensure their survival. These responses imply mechanisms based on gene-environment interaction, such as chromatin modification, that results in long-lasting adaptation of gene expression without altering genome integrity

Summary

Introduction

Are we the mere result of our genes? The decoding of the human genome at the turn of the millennium has opened the hope of discovering the most hidden mechanisms responsible for the organism phenotype. Epigenetic marks are the result of complex enzymes/chromatin interactions that establish and maintain different gene expression programs in specific cell types, leading to phenotypically different tissues despite the same genetic information, and ensure short and/or long lasting-heritable response of the organism to the changing environment [4]. Epigenetic mechanisms include several gene expression regulation pathways: 1) the DNA methylation, 2) the histone tail post translational modifications and 3) the noncoding

Results

Conclusion