Épigénétique

Épigénétique is a field of biology that studies heritable changes in gene expression that do not involve alterations to the underlying DNA sequence. These changes can affect how cells read the genes, leading to different traits or cellular functions without changing the genetic code itself. Think of it like the instructions for assembling a Lego set. The Lego bricks themselves (DNA) remain the same, but the epigenetics might determine which instructions are followed at a particular time, or how loudly those instructions are read.

The primary mechanisms of epigenetic regulation include DNA methylation, histone modification, and non-coding RNA. DNA methylation involves the addition of a methyl group to DNA, often leading to gene silencing. Histone modifications alter the structure of chromatin, the complex of DNA and proteins that forms chromosomes, which can either facilitate or repress gene transcription. Non-coding RNAs are RNA molecules that are not translated into proteins but can regulate gene expression through various means.

These epigenetic modifications are not permanent and can be influenced by environmental factors such as diet, stress, and exposure to toxins. This plasticity allows organisms to adapt to changing conditions. Epigenetic changes can also play a crucial role in development, cell differentiation, and disease, including cancer. Research in epigenetics aims to understand how these mechanisms function and how they can be targeted for therapeutic interventions.