Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Knocking the Sox off early mammalian development

31.12.2002


Scientists find key embryonic stem cell gene



Scientists have identified a gene that is required during early mammalian embryogenesis to maintain cellular pluripotency – the ability of an embryonic cell to develop into virtually any cell type of the adult animal. This discovery by Dr. Robin Lovell-Badge and colleagues at the MRC National Institute for Medical Research (London, UK) that the Sox2 gene is necessary to sustain the developmental plasticity of embryonic cells sheds new light on the molecular cues that direct early embryogenesis, as well as the genetic requirements for embryonic stem cell maintenance. The report is published in the January 1 issue of Genes & Development.

"Stem cells must have specific genes that give them their characteristic properties. Our work describes one such gene, Sox2, that appears essential for multipotent stem cell types in the early embryo," explains Dr. Lovell-Badge.


Early in mammalian development, a pre-implantation stage embryo called a blastocyst forms. The cells of the blastocyst are at a developmental fork in the road: The cells on the surface of the blastocyst become trophoblast cells, while the cells on the inside of the blastocyst become the inner cell mass (ICM). The ICM is further specified into epiblast and hypoblast cells, which, together with trophoblast cells, give rise to the entire embryo and its associated tissues: epiblast cells differentiate into all the cell types of the embryo, hypoblast cells differentiate into the yolk sac, and trophoblast cells differentiate into the chorion and much of the placenta, including a range of specialized cell types.

Dr. Lovell-Badge and colleagues have identified Sox2 as one of the only two known transcription factors (master gene regulators) to be involved in the specification of these three embryonic cell lineages.

"We have been working with this gene for a while, using it, for example, to study stem cells of the nervous system, and simply set out to ask what its critical role is during embryonic development. It turned out to be important very early on - well before the nervous system forms - in two separate cell types: those that give rise to all cells types of the embryo and those that give rise to much of the placenta," states Dr. Lovell-Badge.

To investigate the developmental role of Sox2, the researchers generated transgenic mice deficient in the gene, or what scientists call "Sox2 knockout mice." Sox2 knockout mice die as embyos shortly after implantation in the uterus. Dr. Lovell-Badge and colleagues noted that while maternally derived SOX2 protein is present in newly formed embryos, by embryonic day 6.5 the maternal levels of SOX2 dissipate and fatal defects arise in Sox2-deficient embryos.

The researchers found that in Sox2-deficient embryos, the epiblast lineage fails, and only a portion of trophoblast- and hypoblast-derived cells survive. Further work in cell culture confirmed this result in vitro, and also demonstrated that embryonic stem cells cannot be derived from Sox2-deficient embryos. Thus, Sox2 is required to maintain cellular pluripotency both in the developing embryo and in embryonic stem cells.

With this discovery, Sox2 now joins Oct4 as the only identified transcription factors crucial to maintaining embryonic pluripotency. Dr. Lovell-Badge and colleagues show that Sox2 is actually expressed in a broader range than Oct4 in the embryo: While the expression of both genes is required in the ICM and epiblast, only Sox2 is also required to sustain multipotential cells derived from the trophoblast lineage.

Although further research is needed to delineate the precise molecular pathway of Sox2 action, Dr. Lovell-Badge feels confident that Sox2 "helps to define an embryonic stem cell (ES cell) – [and] it will therefore allow us to better understand these cells and perhaps to manipulate them in ways that will be important for stem cell based therapies."

Heather Cosel | EurekAlert!

More articles from Life Sciences:

nachricht Insights into the origin of life: how the first protocells divided
19.02.2020 | Universität Augsburg

nachricht Superresolution live-cell imaging provides unexpected insights into the dynamic structure of mitochondria
18.02.2020 | Heinrich-Heine-Universität Düsseldorf

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

Im Focus: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

Im Focus: Quantum fluctuations sustain the record superconductor

Superconductivity approaching room temperature may be possible in hydrogen-rich compounds at much lower pressures than previously expected

Reaching room-temperature superconductivity is one of the biggest dreams in physics. Its discovery would bring a technological revolution by providing...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Time-resolved measurement in a memory device

19.02.2020 | Physics and Astronomy

Mixed-signal hardware security thwarts powerful electromagnetic attacks

19.02.2020 | Information Technology

Could water solve the renewable energy storage challenge?

19.02.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>