Featured Research

from universities, journals, and other organizations

UNC Study Pinpoints Gene Crucial For Female Embryo Survival; Gene Keeps Paternal X Chromosome Inactive

Date:
July 23, 2001
Source:
University Of North Carolina School Of Medicine
Summary:
A gene discovered by scientists at the University of North Carolina at Chapel Hill appears to be crucial for female embryo survival.

CHAPEL HILL - A gene discovered by scientists at the University of North Carolina at Chapel Hill appears to be crucial for female embryo survival.

Related Articles


A study authored by UNC researchers and published in the August issue of "Nature Genetics" furthers the understanding of a fundamental biological process in mammals and contributes important new knowledge to gene regulation in the developing embryo. It also has implications for problems such as fetal loss, tumor development, birth defects and mental retardation.

The report notes that the gene, eed, when functioning normally in female mouse embryos, keeps the paternal X chromosome inactive and many of its genes shut down in early placental cells. In the new research, female embryos without a functioning eed do not survive because of problems in forming placentas.

Other studies have shown that the gene Xist is responsible for putting the molecular brakes only on the X chromosome. As female mammals have two X chromosomes (XX) and males an X and Y (XY), imbalance occurs because female embryos have twice as many X-linked genes.

That's where Xist comes into play. It gets turned on early in the development of the female embryo. This gene is activated from the X chromosome that's going to be shut down, which in early placental material is only the X from the father, according to Terry Magnuson, PhD, senior author of the new study and Kenan professor of genetics at UNC-CH School of Medicine.

"Once the paternal X chromosome is shut down, then the cells must continue to divide and keep it shut down. Until now, it's not been understood what maintains this X in an inactivated state. Now we know that eed plays a role in this process," said Magnuson.

"Without eed functioning normally, the father's X chromosome is shut down and then it comes back on. When that happens, too many X chromosome genes are active, there are problems forming placental tissue, and female embryos die."

Magnuson pointed out that X inactivation also occurs within the embryo itself, not just in early placental (trophoblast) material surrounding the embryo. However, this occurs randomly since about 50 percent of the time either the paternal or a maternal X chromosome is shut down.

The new findings also suggest that eed may be critical in a fundamental process known as imprinting, a phenomenon in which a specific gene is expressed, or turned on, depending on whether it is inherited from the mother or the father.

"We know that this gene [eed] does other things as well. It's involved in tumor genesis. If the gene is mutated in a way that is less severe, where the protein is still produced and still functions but not to optimal efficiency, then the animals come to term and are susceptible to developing leukemias. They also have skeletal and other problems." Magnuson said.

"This gene is also involved in telling cells where to go in the embryo - to make head versus tail versus gut. Without this gene functioning in the proper way, those cells move to the wrong place. And that can result in birth defects.

"We've learned from the human genome projects that there are far fewer genes than were originally estimated, roughly 35,000. In a complex organism like humans, those 35,000 genes must act in concert with one another in many different combinations at many different times," Magnuson said.

"So understanding how genes are regulated in terms of their expression, how they are turned on and off, and if they are off how they are maintained in that 'off' state, becomes critical in the post-genome era of understanding gene function."

Magnuson's principal co-authors are Jianbo Wang, PhD and graduate student Jesse Mager. Other UNC authors from the department of genetics are postdoctoral fellow Yijing Chen, PhD and research assistant Elizabeth Schneider. Other study co-authors are James C. Cross, PhD of the University of Calgary, Alberta, Canada and Andras Nagy, PhD, of the Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Canada.

The study was funded by a grant from the National Institute of Child Health and Human Development. UNC-CH has committed at least $245 million over the next decade to the emerging field of genome sciences. The campuswide initiative, headed by Magnuson and which represents public and private investments, will allow Carolina to be a driving force in determining how the genomics revolution will change the way we treat human diseases, design drugs and grow crops. This collaborative effort includes construction of four new buildings to house genomics research, more than $50 million in recurring funds for 40 new faculty positions and a $25 million anonymous gift to create the Michael Hooker Center for Proteomics to study a specialized area of genetics. For more information on the genome sciences initiative, go to http://www.unc.edu/genome.


Story Source:

The above story is based on materials provided by University Of North Carolina School Of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University Of North Carolina School Of Medicine. "UNC Study Pinpoints Gene Crucial For Female Embryo Survival; Gene Keeps Paternal X Chromosome Inactive." ScienceDaily. ScienceDaily, 23 July 2001. <www.sciencedaily.com/releases/2001/07/010723101639.htm>.
University Of North Carolina School Of Medicine. (2001, July 23). UNC Study Pinpoints Gene Crucial For Female Embryo Survival; Gene Keeps Paternal X Chromosome Inactive. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2001/07/010723101639.htm
University Of North Carolina School Of Medicine. "UNC Study Pinpoints Gene Crucial For Female Embryo Survival; Gene Keeps Paternal X Chromosome Inactive." ScienceDaily. www.sciencedaily.com/releases/2001/07/010723101639.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Botswana Talks to End Illegal Wildlife Trade

Botswana Talks to End Illegal Wildlife Trade

AFP (Mar. 25, 2015) Experts are gathering in Botswana to try to end the illegal wildlife trade that is decimating populations of elephants, rhinos and other threatened species. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Elephants Help Keep 18-Wheeler From Toppling Over

Elephants Help Keep 18-Wheeler From Toppling Over

Newsy (Mar. 25, 2015) The Natchitoches Parish Sheriff&apos;s Office discovered two elephants keeping a tractor-trailer that had gotten stuck in some mud upright on a highway. Video provided by Newsy
Powered by NewsLook.com
Baby 'pet' Orangutan Rescued from Chicken Cage Takes First Steps

Baby 'pet' Orangutan Rescued from Chicken Cage Takes First Steps

Reuters - Light News Video Online (Mar. 25, 2015) Buti, a baby orangutan who was left malnourished in a chicken cage before his rescue, takes his first steps after months of painful physical therapy. Mana Rabiee reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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