Second code, or what determines actively transcribed regions and replication origins

• Main Author: Konrad Winnicki
• Format: Article
• Language: English
• Published: Index Copernicus International S.A. 2009-04-01
• Series: Postępy Higieny i Medycyny Doświadczalnej
• Subjects: epigenetic code; DNA Methylation; H3 and H4 histone modifications
• Online Access: http://journals.indexcopernicus.com/fulltxt.php?ICID=883993

Although each cell of a complex organism is governed by the same genome, cells which form different tissues vary in epigenetic codes that are responsible for various gene expression. These codes, through their influence on chromatin structure, determine actively transcribed regions and have indirect impact on replication timing. Cytosine methylation and histone modifications, for example the deacetylation and methylation of Lys9 in histone H3, play important roles in forming and transferring epigenetic codes to the next cell generation. The correct copying of such modifications is important for embryonic development, histogenesis, and future functions of the whole organism, and any disturbance can cause abnormal development or disease, such as cancer.