Featured Research

from universities, journals, and other organizations

Therapeutic Cloning Gets A Boost With New Research Findings

Date:
March 26, 2009
Source:
University of Texas at San Antonio
Summary:
New research offers the first direct demonstration that cloning by somatic cell nuclear transfer does not lead to an increase in the frequency of point mutations.

Germ cells, the cells which give rise to a mammal's sperm or eggs, exhibit a five to ten-fold lower rate of spontaneous point mutations than adult somatic cells, which give rise to the body's remaining cell types, tissues and organs. Despite their comparatively higher mutation rates, however, adult somatic cells are used as the donor cells in a cloning process called somatic cell nuclear transfer (SCNT). This made researchers wonder if cloning by SCNT leads to progeny with more mutations than their naturally conceived counterparts. Also, would cloned fetuses receive DNA programming predisposing them to develop mutations faster than natural fetuses of the same age?

Those scenarios are simply not likely, say researchers at The University of Texas at San Antonio, The University of Texas Health Science Center at San Antonio and The University of Hawaii at Honolulu's John A. Burns School of Medicine. The team, which spent more than five years analyzing mutation rates and types in cloned Big Blue® mouse fetuses recently published its findings in the online Early Edition of the Proceedings of the National Academy of Sciences in a paper titled "Epigenetic regulation of genetic integrity is reprogrammed during cloning."

The paper offers the first direct demonstration that cloning does not lead to an increase in the frequency of point mutations.

John McCarrey, professor of cellular and molecular biology at UTSA and the study's principal investigator, suggests a "bottleneck effect" is partially responsible for the observations his team recorded. "To create a cloned fetus by somatic cell nuclear transfer, only one adult somatic cell -- one donor cell -- is needed," he explains. "Because a random cell population exhibits a low mutation rate overall and only one cell from that population is used for cloning, the likelihood is remote that the cell chosen to be cloned will transfer a genetic mutation to its cloned offspring. Therefore, the bottleneck effect limits the transfer of mutations from donor cells to cloned offspring."

Not only did the researchers find that SCNT does not lead to an increase in the frequency of point mutations in cloned mice, the team also found that naturally conceived fetuses and cloned fetuses that are the same age have similar rates of spontaneous mutation development. They attribute this finding to epigenetic reprogramming.

It is known in the scientific community that germ cells contain an epigenome, a programmed state of the genome, that keeps mutation rates low. They suggest this type of epigenome is found in germ cells because those cells are responsible for contributing genetic information to subsequent generations. Adult somatic cells (the donor cells in SCNT) have higher mutation rates and less stringent epigenetic programming to avoid mutations than germ cells, but offspring produced from somatic cells by cloning have mutation rates similar to those in offspring produced by natural reproduction, suggesting that the epigenome of an adult somatic cell is reprogrammed during cloning to maintain the genetic integrity of that cell's progeny.


Story Source:

The above story is based on materials provided by University of Texas at San Antonio. Note: Materials may be edited for content and length.


Journal Reference:

  1. Patricia Murphey, Yukiko Yamazaki, C. Alex McMahan, Christi A. Walter, Ryuzo Yanagimachi, and John R. McCarrey. Epigenetic regulation of genetic integrity is reprogrammed during cloning. Proceedings of the National Academy of Sciences, 2009; 106 (12): 4731 DOI: 10.1073/pnas.0900687106

Cite This Page:

University of Texas at San Antonio. "Therapeutic Cloning Gets A Boost With New Research Findings." ScienceDaily. ScienceDaily, 26 March 2009. <www.sciencedaily.com/releases/2009/03/090325091805.htm>.
University of Texas at San Antonio. (2009, March 26). Therapeutic Cloning Gets A Boost With New Research Findings. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2009/03/090325091805.htm
University of Texas at San Antonio. "Therapeutic Cloning Gets A Boost With New Research Findings." ScienceDaily. www.sciencedaily.com/releases/2009/03/090325091805.htm (accessed September 18, 2014).

Share This



More Health & Medicine News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) — As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
Powered by NewsLook.com
What HealthKit Bug Means For Your iOS Fitness Apps

What HealthKit Bug Means For Your iOS Fitness Apps

Newsy (Sep. 18, 2014) — Apple has delayed the launch of the HealthKit app platform, citing a bug. Video provided by Newsy
Powered by NewsLook.com
Residents Vaccinated as Haiti Fights Cholera Epidemic

Residents Vaccinated as Haiti Fights Cholera Epidemic

AFP (Sep. 18, 2014) — Haitians receive the second dose of the vaccine against cholera as part of the UN's vaccination campaign. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) — Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins