Navigation Links
UNC researchers identify seventh and eighth bases of DNA
Date:7/21/2011

(Embargoed) CHAPEL HILL For decades, scientists have known that DNA consists of four basic units -- adenine, guanine, thymine and cytosine. Those four bases have been taught in science textbooks and have formed the basis of the growing knowledge regarding how genes code for life. Yet in recent history, scientists have expanded that list from four to six.

Now, with a finding published online in the July 21, 2011, issue of the journal Science, researchers from the UNC School of Medicine have discovered the seventh and eighth bases of DNA.

These last two bases called 5-formylcytosine and 5 carboxylcytosine are actually versions of cytosine that have been modified by Tet proteins, molecular entities thought to play a role in DNA demethylation and stem cell reprogramming.

Thus, the discovery could advance stem cell research by giving a glimpse into the DNA changes such as the removal of chemical groups through demethylation that could reprogram adult cells to make them act like stem cells.

"Before we can grasp the magnitude of this discovery, we have to figure out the function of these new bases," said senior study author Yi Zhang, Ph.D., Kenan Distinguished Professor of biochemistry and biophysics at UNC and an Investigator of the Howard Hughes Medical Institute. "Because these bases represent an intermediate state in the demethylation process, they could be important for cell fate reprogramming and cancer, both of which involve DNA demethylation."

Much is known about the "fifth base," 5-methylcytosine, which arises when a chemical tag or methyl group is tacked onto a cytosine. This methylation is associated with gene silencing, as it causes the DNA's double helix to fold even tighter upon itself.

Last year, Zhang's group reported that Tet proteins can convert 5 methylC (the fifth base) to 5 hydroxymethylC (the sixth base) in the first of a four step reaction leading back to bare-boned cytosine. But try as they might, the researchers could not continue the reaction on to the seventh and eighth bases, called 5 formylC and 5 carboxyC.

The problem, they eventually found, was not that Tet wasn't taking that second and third step, it was that their experimental assay wasn't sensitive enough to detect it. Once they realized the limitations of the assay, they redesigned it and were in fact able to detect the two newest bases of DNA. The researchers then examined embryonic stem cells as well as mouse organs and found that both bases can be detected in genomic DNA.

The finding could have important implications for stem cell research, as it could provide researchers with new tools to erase previous methylation patterns to reprogram adult cells.

It could also inform cancer research, as it could give scientists the opportunity to reactivate tumor suppressor genes that had been silenced by DNA methylation.


'/>"/>

Contact: Les Lang
llang@med.unc.edu
919-966-9366
University of North Carolina School of Medicine
Source:Eurekalert  

Related medicine news :

1. Researchers map all the fragile sites of the yeast Saccharomyces cerevisiaes genome
2. UH Case Medical Center researchers publish promising findings for advanced cervical cancer
3. Researchers discover new way to kill pediatric brain tumors
4. Researchers Who Discovered First Genes for Stuttering will Present Findings to the National Stuttering Association
5. Researchers create drug to keep tumor growth switched off
6. Urine protein test might help diagnose kidney damage from lupus, UT Southwestern researchers find
7. GUMC researchers say flower power may reduce resistance to breast cancer drug tamoxifen
8. Clemson researchers develop hands-free texting application
9. Researchers find biomarkers in saliva for detection of early-stage pancreatic cancer
10. Researchers chart genomic map spanning over 2 dozen cancers
11. Researchers discover second protective role for tumor-suppressor
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
UNC researchers identify seventh and eighth bases of DNA
(Date:10/13/2017)... NY (PRWEB) , ... October 13, 2017 , ... Ellevate ... people in business to advocate for action towards gender equality at their inaugural Summit ... from around the globe, and reached a social audience of over 3 million. To ...
(Date:10/13/2017)... ... October 13, 2017 , ... “The Journey: From the Mountains to the ... save lost souls in the Philippines. “The Journey: From the Mountains to the Mission ... of the Bible. She has taught all ages and currently teaches a class of ...
(Date:10/12/2017)... ... 12, 2017 , ... The company has developed a suite ... regulatory authorities worldwide. From Children’s to Adults 50+, every formula has been developed ... , These products are also: Gluten Free, Non-GMO, Vegan, Soy Free, Non-Dairy*, ...
(Date:10/12/2017)... LOS ANGELES (PRWEB) , ... October 12, 2017 ... ... of Parsa Mohebi Hair Restoration, has recently contributed a medical article to the ... doctors, on cosmetictown.com. Dr. Mohebi’s article spotlights the hair transplant procedure known as ...
(Date:10/12/2017)... ... ... Health Literacy Innovations (HLI), creator of the Health Literacy ... Patient Education Network (CPEN), an independent professional organization that shares best practices in ... , As CPEN’s strategic partner, HLI will help support CPEN members by sharing ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... Mich. , Oct. 2, 2017 Diplomat ... 8th Day Software and Consulting, LLC , and ... 8th Day Software, based in Tennessee ... LLC. 8th Day expands EnvoyHealth,s service offerings for health ... development. "In an ...
(Date:10/2/2017)... Oct. 2, 2017 Halo Labs announces the European launch ... called the HORIZON at MIBio 2017 in Cambridge, U.K ... visible particulate matter in biopharmaceutical samples with unprecedented speed and sensitivity ... novel technique Backgrounded Membrane Imaging. ... The HORIZON subvisible particle analysis system ...
(Date:9/28/2017)... 2017 Cohen Veterans Bioscience and Early Signal ... wearable and home sensors for real-time monitoring of patients ... a nonprofit organization focused on disruptive health solutions for ... analytical system to record and integrate behavioral, cognitive, physiological ... ...
Breaking Medicine Technology: