A topologically associating domain (TAD) is a self-interacting genomic region, meaning that DNA sequences within a TAD physically interact with each other more frequently than with sequences outside the TAD. The median size of a TAD in mouse cells is 880 kb, and they have similar sizes in non-mammalian species. Boundaries at both side of these domains are conserved between different mammalian cell types and even across species and are highly enriched with CCCTC-binding factor (CTCF) and cohesin. In addition, some types of genes (such as transfer RNA genes and housekeeping genes) appear near TAD boundaries more often than would be expected by chance.
The functions of TADs are not fully understood and are still a matter of debate. Most of the studies indicate TADs regulate gene expression by limiting the enhancer-promoter interaction to each TAD; however, a recent study uncouples TAD organization and gene expression. Disruption of TAD boundaries are found to be associated with wide range of diseases such as cancer, variety of limb malformations such as synpolydactyly, Cooks syndrome, and F-syndrome, and number of brain disorders like Hypoplastic corpus callosum and Adult-onset demyelinating leukodystrophy.
The mechanisms underlying TAD formation are also complex and not yet fully elucidated, though a number of protein complexes and DNA elements are associated with TAD boundaries. However, the handcuff model and the loop extrusion model describe the TAD formation by the aid of CTCF and cohesin proteins. Furthermore, it has been proposed that the stiffness of TAD boundaries itself could cause the domain insulation and TAD formation.
TADs are defined as regions whose DNA sequences preferentially contact each other. They were discovered in 2012 using chromosome conformation capture techniques including Hi-C. They have been shown to be present in multiple species, including fruit flies (Drosophila), mouse, plants, fungi and human genomes. In bacteria, they are referred to as Chromosomal Interacting Domains (CIDs).
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
The goal of the course is to guide students through the essential aspects of molecular neuroscience and neurodegenerative diseases. The student will gain the ability to dissect the molecular basis of
Le but du cours est de fournir un aperçu général de la biologie des cellules et des organismes. Nous en discuterons dans le contexte de la vie des cellules et des organismes, en mettant l'accent sur l
This advanced Bachelor/Master level course will cover fundamentals and approaches at the interface of biology, chemistry, engineering and computer science for diverse fields of synthetic biology. This
Delves into neuroepigenetics, covering chromatin structure, histone modifications, DNA methylation, and their impact on gene transcription and inheritance.
Explores neuroepigenetics, focusing on chromatin structure, regulation, and epigenetic inheritance in neurodevelopment.
Explores chromatin structure, DNA compaction, and regulatory networks in genomics.
Since Strahl and Allis proposed the "language of covalent histone modifications", a host of experimental studies have shed light on the different facets of chromatin regulation by epigenetic mechanisms. Initially proposed as a concept for controlling gene ...
An insulator is a type of cis-regulatory element known as a long-range regulatory element. Found in multicellular eukaryotes and working over distances from the promoter element of the target gene, an insulator is typically 300 bp to 2000 bp in length. Insulators contain clustered binding sites for sequence specific DNA-binding proteins and mediate intra- and inter-chromosomal interactions. Insulators function either as an enhancer-blocker or a barrier, or both.
In genetics, an enhancer is a short (50–1500 bp) region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur. These proteins are usually referred to as transcription factors. Enhancers are cis-acting. They can be located up to 1 Mbp (1,000,000 bp) away from the gene, upstream or downstream from the start site. There are hundreds of thousands of enhancers in the human genome. They are found in both prokaryotes and eukaryotes.
Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication. During mitosis and meiosis, chromatin facilitates proper segregation of the chromosomes in anaphase; the characteristic shapes of chromosomes visible during this stage are the result of DNA being coiled into highly condensed chromatin.
This journal club by Elisa Oricchio highlights two studies published in 2012, which used chromatin conformation capture methods to detect the formation of self-interacting chromatin regions, known as topologically associating domains (TADs). ...
During gastrulation, Hox genes are activated in a timesequence that follows the order of the genes along their clusters. This property, which is observed in all animals that develop following a progressive rostral-to-caudal morphogenesis, is associated wit ...