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 New mechanisms uncovered explaining frost tolerance in plants
26.09.2016 | Technische Universität München

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Stronger turbine blades with molybdenum silicides

26.09.2016 | Materials Sciences

Scientists Find Twisting 3-D Raceway for Electrons in Nanoscale Crystal Slices

26.09.2016 | Materials Sciences

Lowering the Heat Makes New Materials Possible While Saving Energy

26.09.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>