Chromatin is the molecular substance of a chromosome. It consists of a complex of DNA, RNA and protein in eukaryotic cells. Frequently, people encounter pictures of chromosomes which have a striped pattern of stronger and lighter staining. What are these chromosome bands? Do they represent genes? No, they do not necessarily represent genes nor do they automatically correspond to stretches lacking genes. Chromosomes often presented to the public are most highly compacted metaphase chromosomes or the giant chromosomes (i.e. polytene chromosome) of Drosophila larvae from salivary gland cells. The latter are made up of about 2000 DNA double strands arranged parallel to each other. A single band of a Drosophila giant chromosome can contain about 50.000 nucleotides in a row. But what makes its staining different to an adjacent band? What we see as dark bands is a consequence of an increased concentration of DNA within variably, compacted chromatin that differs in staining on average every 50 kb. But there is also a gradient of diverse higher order degrees of compaction. Further, in the life of a chromosome it alters its appearance. During the so-called interphase it is relaxed with a lot of open chromatin (see FAQ 7). During this phase, some entire chromosomes but mostly only parts thereof retain a strong staining. These subnuclear features are known since the early days of cytology. In 1928, Heitz introducd for them the term 'heterochromatin'. Euchromatin, on the other hand, is highly decondensed chromatin. Chromosomal regions in the genome which lack high numbers of genes are normally compacted in heterochromatin while chromosomal regions with high concentrations of transcribed genes are part of relaxed euchromatin. But these patterns change during development depending on the pattern of particular epigenetic tags present in the chromatin (see FAQ 8).
The Asia Epigenome Meeting is an annual event that rotates in South Korea, Japan, China, Taiwan, Singapore and India. It is to engage world leading scientists and outstanding Asia researchers to promo...
- Academia Sinica
Metabolism and Epigenetics are intricately linked, playing a key role in development, cancer, immune signaling and aging. This symposium brings together world-leading researchers exploring this nexus....
- Heidelberg, Germany
Meeting in Paris
More than 280 scientists attended the fifth Annual Meeting of EpiGeneSys. The conference kicked off with a talk by coordinator Geneviève Almouzni, Director of the Research Center at the Institut Curie, highlighting the achievements of the network over more than five years...
The Non-Coding Genome ...
The last training workshop of the EpiGeneSys network
Paris / TriRhena Chromatin Club
...exciting talks and network with members of the Chromatin community!
... An EpiGeneSys TAB workshop
... learn about current approaches to single cell epigenetics and to meet up and network with...
The Histone Acetyltransferase Mst2 Protects Active Chromatin from Epigenetic Silencing by Acetylating the Ubiquitin Ligase Brl1.Read more
Proliferation Drives Aging-Related Functional Decline in a Subpopulation of the Hematopoietic Stem Cell Compartment.Read more
The impact of rare and low-frequency genetic variants in common disease.Read more