Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Knocking the Sox off early mammalian development


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 Molecular doorstop could be key to new tuberculosis drugs
20.03.2018 | Rockefeller University

nachricht Modified biomaterials self-assemble on temperature cues
20.03.2018 | Duke 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: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Scientists invented method of catching bacteria with 'photonic hook'

20.03.2018 | Physics and Astronomy

Next Generation Cryptography

20.03.2018 | Information Technology

Science & Research
Overview of more VideoLinks >>>