Featured Research

from universities, journals, and other organizations

Stem Cell Discovery Sheds Light On Placenta Development

Date:
June 11, 2008
Source:
University of Florida
Summary:
By manipulating a specific gene in a mouse blastocyst -- the structure that develops from a fertilized egg but is not yet an actual embryo -- scientists caused cells destined to build an embryo to instead change direction and build the cell mass that leads to the placenta.

Researchers studying embryonic stem cells have explored the first fork in the developmental road, getting a new look at what happens when fertilized eggs differentiate to build either an embryo or a placenta.

Related Articles


By manipulating a specific gene in a mouse blastocyst -- the structure that develops from a fertilized egg but is not yet an actual embryo -- scientists with the University of Florida's McKnight Brain Institute and the Harvard Stem Cell Institute caused cells destined to build an embryo to instead change direction and build the cell mass that leads to the placenta.

Writing in the June 9 online edition of Nature Genetics, the scientists reveal a cellular signaling mechanism in place at the earliest developmental stage.

Understanding the conditions that cause these cells to go off to different fates may have a bearing on health problems such as ectopic pregnancy, which occurs when the embryo develops outside of the womb in about 1 of 60 pregnancies, or molar pregnancy, which is abnormal tissue growth within the uterus that affects about 1 in every 1,000 pregnancies.

"We originally were exploring factors that might cause embryonic stem cells to become malignant -- there is a concern that these cells may cause tumors," said Chi-Wei Lu, Ph.D., an associate neuroscientist at the UF College of Medicine and lead author of the study. "Our experiments led us to discover the signal that initiates the process of embryonic tissue differentiation."

By activating a gene called Ras in cells bathed in a very specific culture medium, scientists were able to cause embryonic stem cells -- which originate from the inner cell mass of the blastocyst -- to become more like the trophoblastic stem cells that give rise to the placenta from the outer portion of the blastocyst.

Researchers marked these newly minted cells, which they called ES-TS cells, and injected them into mouse embryos. Instead of joining the stem cells that build the embryo, ES-TS cells joined the stem cells that build the placenta. Furthermore, when scientists transferred the engineered mouse embryos to foster mothers, the ES-TS cells went to work exclusively laying the foundation for the placenta.

"This paper highlights the value of embryonic stem cells for understanding early development," said senior author George Q. Daley, M.D., Ph.D., an associate professor of biological chemistry and molecular pharmacology at Harvard Medical School and an associate professor of pediatrics at Children's Hospital Boston. "Embryonic stem cells are more plastic than we had thought. By simply activating the Ras gene, we changed the fate of embryonic stem cells to an entirely unexpected tissue -- the placenta. This surprising result has given us an unanticipated insight into early embryo development."

The technique of genetically modifying the cells and growing them in a special medium could be valuable for additional research.

"This is exciting because events that only occur in the early stages of embryonic development are very difficult to study," Lu said. "Just a few models exist, and even in mice, only a limited amount of embryos can be harvested. Now we can culture these cells and have unlimited material to study."

Researchers are only beginning to understand the natural chemical environments that allow for production of different tissues.

"What is nice is that what she has observed in cultures appears to be quite similar to what goes on in early development in animals," said R. Michael Roberts, D.Phil., a professor of molecular biology at the C.S. Bond Life Sciences Center at the University of Missouri-Columbia who did not participate in the research. "Normally, mouse embryonic stem cells aren't easily converted along the pathway to form placental cells, while human embryonic stem cells undergo this transition quite easily. This has always been a puzzle. What she has shown is you can make mouse embryonic stem cells convert unidirectionally to trophoblasts by activating a single gene. This is very helpful for understanding how the placenta develops."


Story Source:

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


Cite This Page:

University of Florida. "Stem Cell Discovery Sheds Light On Placenta Development." ScienceDaily. ScienceDaily, 11 June 2008. <www.sciencedaily.com/releases/2008/06/080609124547.htm>.
University of Florida. (2008, June 11). Stem Cell Discovery Sheds Light On Placenta Development. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2008/06/080609124547.htm
University of Florida. "Stem Cell Discovery Sheds Light On Placenta Development." ScienceDaily. www.sciencedaily.com/releases/2008/06/080609124547.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
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


Health & Medicine

Mind & Brain

Living & Well

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