Navigation Links
Skin cells reveal DNA's genetic mosaic
Date:11/18/2012

The prevailing wisdom has been that every cell in the body contains identical DNA. However, a new study of stem cells derived from the skin has found that genetic variations are widespread in the body's tissues, a finding with profound implications for genetic screening, according to Yale School of Medicine researchers.

Published in the Nov. 18 issue of Nature, the study paves the way for assessing the extent of gene variation, and for better understanding human development and disease.

"We found that humans are made up of a mosaic of cells with different genomes," said lead author Flora Vaccarino, M.D., the Harris Professor of Child Psychiatry at the Yale Child Study Center. "We saw that 30 percent of skin cells harbor copy number variations (CNV), which are segments of DNA that are deleted or duplicated. Previously it was assumed that these variations only occurred in cases of disease, such as cancer. The mosaic that we've seen in the skin could also be found in the blood, in the brain, and in other parts of the human body."

The longstanding belief has been that our cells have the same DNA sequence and this blueprint governs the body's functions. The Yale team's research challenges this dogma. Some scientists have hypothesized that during development, when DNA is copied from mother to daughter cells, there could be deletions, duplications and changes in the sequence of the DNA, and an entire group of genes could be affected. This premise has been incredibly difficult to test, but Vaccarino and colleagues have done so in this new study.

The team used whole genome sequencing to study induced pluripotent stem cells lines (iPS), which are stem cells developed from a mature-differentiated cell. The team grew cells taken from the inner upper arms of two families. The team spent two years characterizing these iPS cell lines and comparing them to the original skin cells.

While observing that the genome of iPS cells closely resembles the genome of skin cells from which they originated, the team could identify several deletions or duplications involving thousands of base pairs of DNA. The team then performed additional experiments to understand the origin of those differences, and showed that at least half of them pre-existed in small fractions of skin cells. These differences were revealed in iPS cells because each iPS line is derived from one, or very few, skin cells. Vaccarino said these iPS lines could act as a magnifying glass to see the mosaic of genomic differences in the body's cells.

"In the skin, this mosaicism is extensive and at least 30 percent of skin cells harbor different deletion or duplication of DNA, each found in a small percentage of cells," said Vaccarino. "The observation of somatic mosaicism has far-reaching consequences for genetic analyses, which currently use only blood samples. When we look at the blood DNA, it's not exactly reflecting the DNA of other tissues such as the brain. There could be mutations that we're missing."

"These findings are shaping our future studies, and we're doing more studies of the developing brains of animals and humans to see if this variation exists there as well," Vaccarino added.


'/>"/>

Contact: Karen N. Peart
karen.peart@yale.edu
203-432-1326
Yale University
Source:Eurekalert

Related biology news :

1. Tortoise and the hare: New drug stops rushing cancer cells, slow and steady healthy cells unharmed
2. Stem cells can repair a damaged cornea
3. Scientists produce eye structures from human blood-derived stem cells
4. Study demonstrates cells can acquire new functions through transcriptional regulatory network
5. Epigenetic signatures direct the repair potential of reprogrammed cells
6. Researchers print live cells with a standard inkjet printer
7. Nanopills release drugs directly from the inside of cells
8. Protein jailbreak helps breast cancer cells live
9. Newly found protein helps cells build tissues
10. BU researchers derive purified lung and thyroid progenitors from embryonic stem cells
11. Housekeeping mechanism for brain stem cells discovered
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/5/2016)... 2016 http://www.researchandmarkets.com/research/5kvw8m/global_facial ) ... "Global Facial Recognition Market 2016-2020" report ... ) has announced the addition of the ... report to their offering. --> ... announced the addition of the "Global ...
(Date:2/3/2016)... Vigilant Solutions announces today that the ... Missouri solved two recent hit-and-run cases with ... Vigilant Solutions. Brian Wenberg explains, "I ... was walking out of a convenience store and witnessed an elderly male back ... striking his vehicle and leaving the scene.  In his ...
(Date:2/2/2016)... Checkpoint Inhibitors for Cancer – Explore ... you interested in the future of cancer drugs? ... Visiongain,s report gives those predictions to 2026 at ... Avoid falling behind in data or losing ... those emerging cancer therapies can achieve. There you ...
Breaking Biology News(10 mins):
(Date:2/8/2016)... R&D program for the development of future natural products for ... research and development center in Israel ... Stockton has a variety of products adapted ... active in more than 35 counties worldwide. ... flagship product Timorex Gold ® is used to control ...
(Date:2/5/2016)... 2016 ATCC, the premier global biological materials ... medical and life science researchers that are working to ... CDC website . --> ... is a single-stranded RNA virus of the Flaviviridae family, ... and Chikungunya Viruses. Zika virus is transmitted to humans ...
(Date:2/4/2016)... ... February 04, 2016 , ... Morf Media Inc ., ... interactive FDA compliance training course, Writing Effective SOPs (Standard ... interactive course on Morf Playbook—now conveniently available on smartphones and PCs--provides step by ...
(Date:2/4/2016)... 2016 Beike Biotechnology, the Shenzhen ... a ceremony in late 2015 to mark their successful ... 2016. --> --> ... Personalized Cell Therapy" was hosted by the Shenzhen Cell ... subsidiaries of Beike Biotechnology Co., Ltd. ...
Breaking Biology Technology: