Navigation Links
Scientists clarify a mechanism of epigenetic inheritance
Date:4/22/2008

tance mechanisms, such as chemical modifications of DNA, that complicate the study of more complex animals and plants.

Long DNA molecules almost miraculously cram into cell nuclei that are almost a million times smaller than they are. They do so by wrapping around proteins called histones, which array themselves along the length of the DNA molecule like beads on a string. These DNA-wrapped histones then form larger arrays. The densely packed mass is then modified chemically by other proteins to form heterochromatin.

The dense packing of heterochromatin hides the DNA sequence from the cellular machinery that reads its genetic information, so the DNA in heterochromatin is silenced. The genes it contains are effectively turned off.

Surprisingly, the clumping persists even after cells divide, although, says Dr. Martienssen, its always been a mystery how modifications of histones could be inherited. A few years ago, however, his group and others solved this mystery. They found that histone modification is controlled by complicated cellular mechanisms broadly known as RNA interference, or RNAi.

In RNAi, RNA that is copied from particular regions of DNA interacts with various proteins to modify histones in the same regions. Because the RNA matches only the section of DNA that produced it, it provides the specificity that you need to make sure that only that part of the chromosome gets these histone modifications, Dr. Martienssen says. If the whole chromosome were to get those histone modifications, youd be dead.

All in the Timing

These results raised a new puzzle, though: Since genes contained within heterochromatin are silenced, how can they give rise to the RNA molecules that help to modify histones? In new research, Martienssens team has now solved this puzzle by tracking the cells through their cycle of growth and division.

They found that the interfering RNA molecules appear only during the brie
'/>"/>

Contact: Jim Bono
bono@cshl.edu
516-367-8455
Cold Spring Harbor Laboratory
Source:Eurekalert

Page: 1 2 3

Related biology news :

1. Scientists to explore global change-public health connection
2. Scientists test device to track medication adherence in patients with HIV/AIDS
3. Scientists discover how nanocluster contaminants increase risk of spreading
4. Smithsonian scientists find evidence that could rewrite Hawaiis botanical history
5. Argonne scientists develop techniques for creating molecular movies
6. Scientists debate the accuracy of Al Gores documentary An Inconvenient Truth
7. Scientists compiled 20th century temperature data in Spain as evidence of climatic change
8. Atmospheric scientists gear up for collaborative airborne campaigns
9. AMNH scientists grace Science & Nature covers
10. Scientists uncover the potential to control adult stem cells
11. Scientists ask whether microscaffolding can help stem cells rebuild brain after stroke damage
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/16/2014)... have challenged conventional thinking on how the bowel lining ... for how bowel cancer starts. , The researchers produced ... regenerating the ,crypts, that are a feature of the ... in bowel cancer development, a controversial finding as scientists ... Using 3D imaging technologies, Dr Chin Wee Tan and ...
(Date:10/16/2014)... , October 16, 2014 NXT-ID, Inc. (NASDAQ: ... "Company"), a biometric authentication company focused on the growing ... edge technologies including Wocket™, the Smart Wallet, at the ... FiRe is a leading global conference on the intersection ... by Mark Anderson , founder and publisher of ...
(Date:10/15/2014)... has admitted Johannes Gutenberg University Mainz (JGU) as ... hub continues to maintain a significant nationwide standing ... "The acceptance of Johannes Gutenberg University Mainz as ... milestone in the national and international competition for ... of Rhineland-Palatinate can be proud that Mainz University ...
Breaking Biology News(10 mins):Cryptic clues drive new theory of bowel cancer development 2NXT-ID Inc. to Present at 13th Annual FiRe Conference 2NXT-ID Inc. to Present at 13th Annual FiRe Conference 3Johannes Gutenberg University Mainz joins Germany's Gauss-Allianz as a full member 2Johannes Gutenberg University Mainz joins Germany's Gauss-Allianz as a full member 3
... West Indian tarantula has been shown to cause pain ... sense high temperatures and the hot, spicy ingredient in ... demonstrate that some plants and animals have evolved the ... by activating a specific receptor on sensory nerves. The ...
... gardener knows--different plant species mature at different times. ... this phenomenon "complementarity." It allows many species to ... period when species compete for limited resources. Now, ... Sept. 4 in the Proceedings of the National ...
... the limb regrows. What is more, a newt can also ... Planck Institute for Heart and Lung Research in Bad Nauheim ... impressive ability to regenerate and have discovered the remarkable plasticity ... do not have this ability, the findings could contribute to ...
Cached Biology News:Tarantula venom and chili peppers target same pain sensor 2Global changes alter the timing of plant growth, scientists say 2Global changes alter the timing of plant growth, scientists say 3Newts which regrow their hearts 2
(Date:10/25/2014)... , October 24, 2014 Investor-Edge ... (NASDAQ: CYTR ), Vertex Pharmaceuticals Inc. (NASDAQ: ... ALXN ), Peregrine Pharmaceuticals Inc. (NASDAQ: ... on these five companies can be accessed at: ... October 23, 2014, ended on a positive note as ...
(Date:10/25/2014)... , October 24, 2014 ... Markets ( http://www.researchandmarkets.com/research/t5t5pd/the_global_market ) has announced the addition ... Nanotubes, Graphene And Other 2-D Nanomaterials " ... (Logo: http://photos.prnewswire.com/prnh/20130307/600769) , ,CNTs and graphene are ... known to man, with a performance-per-weight greater ...
(Date:10/22/2014)... , Oct. 22, 2014 Research ... the "Global DNA Diagnostics Market (Product types, ... Share, Global Trends, Company Profiles, Demand, Insights, Analysis, ... 2020" report to their offering. ... (products, applications, techniques, end users and Geography) Global ...
(Date:10/22/2014)... The Americas Inorganic Refrigerants Market report ... Americas with analysis and forecast of revenue. , ... Refrigerants Market report, to get an idea of ... glimpse of the segmentation in the Americas inorganic ... and figures. , http://www.micromarketmonitor.com/market/americas-inorganic-refrigerants-4191654241.html , ...
Breaking Biology Technology:Biotech Stocks Technical Data - CytRx, Vertex Pharma, Alexion Pharma, Peregrine Pharma, and StemCells 2Biotech Stocks Technical Data - CytRx, Vertex Pharma, Alexion Pharma, Peregrine Pharma, and StemCells 3Biotech Stocks Technical Data - CytRx, Vertex Pharma, Alexion Pharma, Peregrine Pharma, and StemCells 4Biotech Stocks Technical Data - CytRx, Vertex Pharma, Alexion Pharma, Peregrine Pharma, and StemCells 5The Global Market for Carbon Nanotubes, Graphene and Other 2-D Nanomaterials 2The Global Market for Carbon Nanotubes, Graphene and Other 2-D Nanomaterials 3The Global Market for Carbon Nanotubes, Graphene and Other 2-D Nanomaterials 4Global DNA Diagnostics Market (Product types, Application, Technology, End User and Geography) - Forecast to 2020 2Global DNA Diagnostics Market (Product types, Application, Technology, End User and Geography) - Forecast to 2020 3The Americas Inorganic Refrigerants Market is estimated to grow to $71.6 million by 2018 - New Report by MicroMarket Monitor 2The Americas Inorganic Refrigerants Market is estimated to grow to $71.6 million by 2018 - New Report by MicroMarket Monitor 3
... Switzerland, August 19 Arpida Ltd,(SIX: ARPN) announced today its financial results ... Key events 2009 to date, - Regulatory setback for ... under review, - Company restructuring completed, , ... June 2009 , CFO Harry Welten, MBA, commented: ...
... , WESTON, Fla., Aug. 19 In keeping with ... of families, America n Scientific Resources ... obtained from Safeguard Medical Technologies, LLC exclusive worldwide rights to sell ... and the Disintegrator Plus(TM). , , All ...
... , , LONDON, Aug. 19 ... the introduction of improved drugs to treat the disease. As healthcare ... companies conducting research on diabetes vaccines. If they succeed, the entire ... (Logo: http://www.newscom.com/cgi-bin/prnh/20081117/FSLOGO ) , , ...
Cached Biology Technology:Arpida Reports Interim Results For Six Months to 30 June 2009 2American Scientific Resources To Be Exclusive Seller of World's Only FDA Approved Home Needle Destruction Device 2American Scientific Resources To Be Exclusive Seller of World's Only FDA Approved Home Needle Destruction Device 3Emergence of Newer Drug Classes to Treat Diabetes and Co-morbidities Key to Market Expansion, Reveals Frost & Sullivan 2Emergence of Newer Drug Classes to Treat Diabetes and Co-morbidities Key to Market Expansion, Reveals Frost & Sullivan 3
... fluorescein-conjugated jetSI-ENDO (excitation at ... nm), the powerful siRNA transfection ... to determine the transfection efficiency ... and trafficking of siRNAs. More ...
... of long double stranded RNA (dsRNA) has ... a diverse group of organisms as well ... leads to the inhibition of protein expression ... target messenger RNA (mRNA). Attempts to induce ...
... lower cost and reduced space requirements ... reference standard DNA analysis technology affordable ... with any of SEQUENOM's applications and ... (iPLEXTM Gold) , Gene Expression Analysis ...
... Bruker Daltonics and Bruker BioSpins Metabolic ... metabolism studies, and analysis of complex ... system, an optional Avance NMR spectrometer ... evaluation and statistical analysis for applications ...
Biology Products: