deciphering-high-resolution-3d-chromatin-organization-via-capture-hi-c

Deciphering High-Resolution 3D Chromatin Organization <em>via</em> Capture Hi-C

The spatial organization of the genome contributes to its function and regulation in many contexts, including transcription, replication, recombination, ...

EMBL: European Molecular Biology Laboratory

How does the folding of the genome relate to the regulation of gene expression? Using fly embryos and quantitative live imaging, a recent study by Yokoshi et al. reveals that the answer might depend on whether enhancer-promoter communication occurs inside or in-between topological domains.

Enhancer-Promoter Communication: Thinking Outside the TAD.

Developmental enhancers drive gene expression in specific cell types during animal development. They integrate signals from many different sources mediated through the binding of transcription factors, producing specific responses in gene expression. Transcription factors often bind low-affinity sequences for only short durations. How brief, low-affinity interactions drive efficient transcription and robust gene expression is a central question in developmental biology. Localized high concentrations of transcription factors have been suggested as a possible mechanism by which to use these enhancer sites effectively. Here, we discuss the evidence for such transcriptional microenvironments, mechanisms for their formation and the biological consequences of such sub-nuclear compartmentalization for developmental decisions and evolution.

Robust and efficient gene regulation through localized nuclear microenvironments.

Early in development, placental and marsupial mammals harbouring at least two X chromosomes per nucleus are faced with a choice that affects the rest of their lives: which of those X chromosomes to transcriptionally inactivate. This choice underlies phenotypical diversity in the composition of tissues and organs and in their response to the environment, and can determine whether an individual will be healthy or affected by an X-linked disease. Here, we review our current understanding of the process of choice during X-chromosome inactivation and its implications, focusing on the strategies evolved by different mammalian lineages and on the known and unknown molecular mechanisms and players involved.

Rafael Galupa

EMBL: European Molecular Biology Laboratory

Deciphering High-Resolution 3D Chromatin Organization via Capture Hi-C