Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stem cell discovery sheds light on placenta development

10.06.2008
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.

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 today's (Monday, 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."

John Pastor | EurekAlert!
Further information:
http://www.ufl.edu

Further reports about: Embryo Embryonic Placenta Tissue embryonic stem embryonic stem cells

More articles from Life Sciences:

nachricht Solving the efficiency of Gram-negative bacteria
22.03.2019 | Harvard University

nachricht Bacteria bide their time when antibiotics attack
22.03.2019 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>