Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How does human embryo begin to develop?

20.07.2011
Hebrew University scientists show for first time how early human embryo acquires its shape through ‘organizer’ cells

How is it that a disc-like cluster of cells transforms within the first month of pregnancy into an elongated embryo? This mechanism is a mystery that man has tried to unravel for millennia.

The first significant step towards understanding the issue was made nearly a century ago in experiments conducted by the German embryologists Hans Spemann and Hilde Mangold. The two used early newt embryos and identified a group of cells within them which, upon transplantation, formed a two-headed tadpole.

In trying to understand why this happened, they concluded that what occurred is that the transplanted cells organized the vicinity into which they were placed to form a typical embryonic shape. They therefore dubbed such cells “organizer” cells. The newt embryo possessed both its own organizers and the transplanted ones, both of which organized nearby cells to form a head structure.

Recently, Israeli scientists from the Hebrew University of Jerusalem have managed to generate human organizer cells, using human embryonic stem cells. Based on the similarity that dominates the initial developmental processes of all vertebrates, the group raised the human cells in conditions which recapitulate those of early amphibian embryogenesis. Within two days, the human cells started expressing genes characteristic of the organizer cells.

To verify that these cells derived from human embryonic stem cells posses a true organizing ability, the researchers repeated Spemann and Mangold’s experiments. Only this time, the human cells, rather than those of amphibians, were transplanted into frog embryos.

The midline of an amphibian embryo is marked by a neural tube – a tissue destined to form the embryo's central nervous system. To the group's astonishment, some of the frog embryos that were transplanted with the human cells possessed not one but two neural tubes. The second tube was composed from frog cells, proving that the injected human cells organized the cells in their vicinity to acquire a tubular shape.

The research was conducted by Nadav Sharon, a graduate student under the supervision of Nissim Benvenisty, the Hebert Cohn Professor of Cancer Research at the Alexander Silberman Institute of Life Sciences at the Hebrew University, in collaboration with Abraham Fainsod, the Wolfson Family Professor of Genetics at the Hebrew University-Hadassah Medical School, and was published in a recent issue of the Stem Cells journal.

Shape determination during human embryonic development is an extremely important process, at which any aberration might lead to miscarriage or the birth of a severely defected newborn. The identification of the human organizer should allow better understanding of this process. Furthermore, the ability of the human organizer cells to shape a frog neural tube may assist in forming human neural tubes in culture, from which neural cells could be obtained for transplantation into people with spinal damage, though much further research would be required to reach that stage.

For further information: Jerry Barach,
Dept. of Media Relations, the Hebrew University,
Tel: 02-588-2904.
Orit Sulitzeanu, Hebrew University spokesperson, Tel: 054-8820016

Jerry Barach | Hebrew University of Jerusalem
Further information:
http://www.huji.ac.il

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>