Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Origin of Cells for Connective Tissues of Skull & Face Challenged

28.05.2008
With improved resolution, tissue-specific molecular markers and precise timing, University of Oregon biologist James A. Weston and colleagues have possibly overturned a long-standing assumption about the origin of embryonic cells that give rise to connective and skeletal tissues that form the base of the skull and facial structures in back-boned creatures from fish to humans.

Weston and co-authors from the Max Planck Institute of Immunology in Germany and the French National Scientific Research Centre at the Curie Institute document their potentially textbook-changing case in an article posted online ahead of regular publication in the Proceedings of the National Academy of Sciences.

The cells in question, they argue, do not come from a portion of embryonic neural epithelium called the neural crest, as widely believed, but rather from a distinct thin layer of epidermal epithelial cells next to it. "Our results," Weston said, "could lead to a better understanding of the etiology of craniofacial defects, as well as the evolution of the head that distinguishes vertebrates from other creatures."

The neural crest was first identified by classical embryologists in the late 19th and early 20th centuries and has been one of the most studied embryonic tissues. Conventional wisdom says that the neural crest gives rise to skeletal and connective tissue of the head and face, as well as a wide diversity of other stem cells that migrate to many places in the vertebrate embryo, where they spawn the cells that create the peripheral nervous system, and pigment cells in skin and hair (or scales and feathers).

The new study is part of research done over 25 years in Weston's quest to understand early development of the neural crest and explore alternative explanations for sometimes differing findings involving its assumed cell lineages. Weston noted that mutations in mice that adversely affected development of the peripheral nervous system or pigmentation did not affect craniofacial structures, whereas mutations that caused abnormal development of skeletal and connective tissue of the head and face did not alter neural crest-derived pigment or peripheral nervous system cells.

This paradox, he said, led him to wonder if different genetic programs were required to function in distinct embryonic precursors of these tissues. "In our new paper," he said, "we finally were able to re-examine some of the underlying assumptions that have led to the conventional wisdom about the source of the embryonic cell lineages that give rise to the skeleton and connective tissue of the head and face."

In the mouse embryo at eight days gestation, Weston and collaborators used high-resolution imaging and immunostaining techniques to identify and track the dispersal of cells known to jump start connective and skeletal tissue development. They were able to see clearly that these cells came from the non-neural layer of cells rather than from the neural crest. The same distinction also exists in chicken embryos during the first few days of gestation, Weston noted. "Looking at the right time is very important," he said.

Weston argues that this non-neural epithelium is indeed distinct from the neural crest, because its cells contain characteristically different molecules. He and colleagues dispute suggestions that this non-neural structure is simply a sub-domain of the neural crest. "These cells emerge at a different time in development and disperse in the embryo before neural crest cells begin to migrate," Weston said.

"New technologies let us see cell types more clearly than ever before," said Weston, a member of the UO's Institute of Neuroscience. "We previously had discovered that a molecule that marks cell surfaces in the non-neural epithelium reveals a very sharp boundary between this non-neural epithelium and the neural tissue connected to the neural crest. In this study, we took a closer look."

They located a population of cells in the non-neural epithelium that express other molecules that "do not appear to originate from the neural crest," said Weston, who retired in 2001 but continued to teach in the College of Arts and Sciences until 2006. He still collaborates in some research with colleagues at the UO and at various labs around the world.

"I think our results have two important messages," he said. "First, it is important to identify and validate -- rather than ignore -- assumptions; and second, because we identified an alternative embryonic cell lineage as the source of the head and facial structures, we can now more effectively analyze and understand the molecular-genetic mechanisms that regulate the normal and abnormal development of these structures."

Co-authors with Weston were Marie Anne Breau, Thomas Pietri, and Jean Paul Thiery, all of the Curie Institute, and Marc P. Stemmler of the Max Planck Institute of Immunobiology. Pietri was a graduate student in the Curie Institute, where the project began in 2002, while Weston was on a fellowship, and now is a postdoctoral researcher with Phil Washbourne in the UO Institute of Neuroscience. Thiery, now based at the Institute of Molecular and Cell Biology of the Agency for Science, Technology and Research in Singapore, is a corresponding author with Weston on the PNAS paper.

About the University of Oregon
The University of Oregon is a world-class teaching and research institution and Oregon's flagship public university. The UO is a member of the Association of American Universities (AAU), an organization made up of 62 of the leading public and private research institutions in the United States and Canada. Membership in the AAU is by invitation only. The University of Oregon is one of only two AAU members in the Pacific Northwest.

Sources: James Weston, professor emeritus of biology, weston@uoneuro.uoregon.edu; Jean Paul Thiery, deputy director, Institute of Molecular and Cell Biology of the Agency for Science, Technology, and Research, +65 6586 9755, jpthiery@imcb.a-star.edu.sg

Links: Weston Web page: http://www.neuro.uoregon.edu/ionmain/htdocs/faculty/weston.html; UO Institute of Neuroscience: http://www.neuro.uoregon.edu/; UO College of Arts and Sciences: http://cas.uoregon.edu/

Jim Barlow | newswise
Further information:
http://www.uoregon.edu

Further reports about: Cell Embryo Embryonic connective crest epithelium neural non-neural uoregon

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>