Navigation Links
Scientists find clue to mechanisms of gene signaling and regulation
Date:8/22/2007

Scientists have discovered a pattern in the DNA sequence of the mouse genome that may play a fundamental part in the way DNA molecules regulate gene expression. The research, led by Emory University scientists along with colleagues at Jacobs University, Bremen, Germany, will be published in the Aug. 22 Advance Online publication of the journal Nature.

Ever since scientists cracked the basic code of chemical bases that comprise the genome of humans and animals, scientists have been uncovering layers of other chemical modifications of gene functioning that can be inherited along with the DNA sequence. This field of discovery, called epigenetics, turns out to be just as important as the genetic sequence itself in controlling whether genes are turned on or off, which determines whether or not they manufacture proteins.

For the past several decades, scientists have known that DNA methylation, a biochemical reaction that adds a methyl group to DNA, is one of these epigenetic processes that marks genes for silencing, which means they do not manufacture proteins. Another kind of modification, called histone methylation, also marks histone proteins that are part of the complex packaging of DNA within the nucleus of cells.

How and where this critical selection process is accomplished--for either silencing or expression-- has been a mystery, however. DNA methylation occurs across the animal genomes, almost always at the C base position of a CG dinucleotide (sequence of two base pairs) in the genetic sequence.

Most expressed genes are based on the simultaneous expression of two copies of a geneone from the mother and one from the father. A small subset of genes, however, are allele-expression specific, meaning only one copy of the gene is expressed, from either the mother or the father, with the gene from the other parent being methylated, or silenced. This kind of differential gene expression is called "imprinting." In the mouse genome, about 80 genes are imprinted.

The Emory and Bremen researchers discovered a biochemical pattern they believe may be a signal to the epigenetic machinery that a particular gene should be imprinted. In the regions of the genome where genes are imprinted, called differentially methylated regions, they found a repeat pattern (periodicity) of 8 to 10 base pairs between two CG dinucleotides. The periodicity is consistent with the structural information from the enzyme responsible for the methylation. The enzyme structure was solved by use of X-ray crystallography at the Advanced Photon Source of Argonne National Laboratory.

"We believe that this repeating pattern of 8 to 10 base pairs between CGs provides a signal for where the differential methylation should take place," says senior author Xiaodong Cheng, PhD, Emory professor of biochemistry and a Georgia Research Alliance eminent scholar. "So far only about 20 regions of differential methylation have been identified in the mouse genome, and we wanted to find out how those regions compared to the rest of the genome."

"Now we can use this new information to find out if any other areas with such 8 to 10 base pair repeats are also differentially methylated. We want to discover how many regions of differential methylation exist and whether or not this imprinting has any impact on disease development."

Scientists already have learned that cancer genes contain "islands" of CG concentrations that are abnormally methylated. Dr. Cheng and his colleagues will focus on these CG islands, trying to discover whether they contain the same repeating pattern as the differentially methylated regions.


'/>"/>
Contact: Holly Korschun
hkorsch@emory.edu
404-727-3990
Emory University
Source:Eurekalert

Related biology news :

1. Wisconsin scientists grow critical nerve cells
2. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
3. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
4. UAB scientists discover the origin of a mysterious physical force
5. Fox Chase Cancer Center scientists identify immune-system mutation
6. Scientists Replicate Hepatitis C Virus in Laboratory
7. Scientists detect probable genetic cause of some Parkinsons disease cases
8. Scientists find missing enzyme for tuberculosis iron scavenging pathway
9. Scientists seek answers on what activates deadly anthrax spores
10. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
11. Scientists collaborate to assess health of global environment
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/22/2016)... , June 22, 2016   ... management and verification solutions, has partnered with ... software solutions for Visitor Management, Self-Service Kiosks ... provides products that add functional enhancements to ... provides corporations and venues with an automated ...
(Date:6/16/2016)... 2016 The global ... reach USD 1.83 billion by 2024, according to ... Technological proliferation and increasing demand in commercial buildings, ... drive the market growth.      (Logo: ... development of advanced multimodal techniques for biometric authentication ...
(Date:6/7/2016)... -- Syngrafii Inc. and San Antonio Credit Union (SACU) ... Syngrafii,s patented LongPen™ eSignature "Wet" solution into SACU,s ... in greater convenience for SACU members and operational ... document workflow and compliance requirements. Logo ... Highlights: ...
Breaking Biology News(10 mins):
(Date:12/2/2016)... IL (PRWEB) , ... December 01, 2016 , ... ... to congratulate long-term client Nanowear on their recent FDA Class II 510(k) clearance ... cleared a significant hurdle in commercializing remote cardiac monitoring devices that rely on ...
(Date:12/2/2016)... , December 2, 2016 The immunohistochemistry ... growing at a CAGR of 7.3% during the forecast period of ... and diagnostic laboratories segment accounted for the largest share of immunohistochemistry ... ... on global immunohistochemistry (IHC) market spread across 225 pages, profiling 10 ...
(Date:11/30/2016)... 2016 The global Pyrogen Testing ... a dominant share in the overall market. The leading ... and Merck KGaA, held a lion,s share of 51% ... observes that these companies are expected to retain their ... are do not require rabbit pyrogen testing along with ...
(Date:11/30/2016)... /PRNewswire/ -  Equicare Health Inc ., the leading supplier ... one of the top 100 companies in the 2016 ... distinguishes the top digital health companies across the globe. ... this year continually upgrading our product with the ongoing ... team," says Len Grenier , CEO of Equicare ...
Breaking Biology Technology: