Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Simply Complex – The Origin of Our Body Axes


Evolutionary ties between humans and prehistoric animals – study published in “Nature”

The fresh-water polyp Hydra, a member of the over 600-million-year-old phylum Cnidaria, is famous for its virtually unlimited regenerative capability and hence a perfect model for molecular stem cell and regeneration research.

This polyp, with its simple structure and radial symmetry, can help us understand how our body axes came to evolve. Scientists from Heidelberg and Vienna have brought this evidence to light through their research on the formation of new polyps in the Hydra through asexual reproduction. Their findings have now been published in the journal “Nature”.

Project participants include a working group under the direction of Prof. Dr. Thomas Holstein and Asst. Prof. Dr. Suat Özbek at the Centre for Organismal Studies (COS) of Heidelberg University and Dr. Heiko Schmidt at CIBIV (Center for Integrative Bioinformatics Vienna) at Max F. Perutz Laboratories (MFPL) of the University of Vienna and the Medical University of Vienna.

The Hydra reproduces asexually by producing buds on the body wall of the adult, which then mature to form new polyps. The Heidelberg researchers delved into this process at the molecular level and discovered that a signal pathway is used that triggers the left-right asymmetry of organs in higher animals, including humans. The processes that play out at the molecular level are strikingly similar to those that trigger the formation of body axes in early embryos of vertebrates.

One fundamental question in biology is what constitutes the basic type of the animal body plan and how did all the more complex forms, including that of humans, evolve from it. At the simplest level, this body plan can be described by the three axes as defined in the Cartesian coordinate system.

These three axes – the familiar X, Y and Z axes from geometry – are the anterior-posterior (AP) axis, which determines the position of the mouth in front and the anus at the rear, the dorsal-ventral (DV) axis, which in vertebrates separates the front of the body from the back, and the left-right (LR) axis, which creates a mirror-like symmetry of our extremities and left-right asymmetry of the organs.

These three body axes are defined early on in embryonic development. A fertilized egg cell begins to divide, initially producing a ball-shaped “heap” of undifferentiated cells. It is in this early stage of the embryo that the position of the first opening of the body is determined, which simultaneously defines the AP axis.

“This process can be explained geometrically as a symmetry break, and other symmetry breaks follow that define the other two axes, the DV and LR axes,” explains Prof. Holstein from the Centre for Organismal Studies (COS).

The genetic basis for each of these body axes had already been identified in the embryonic development of humans, other vertebrates, and even in insects and worms. Evolutionarily highly-conserved molecular signal systems act as molecular vectors to define each of the body axes and control the formation of different cell types. Many of these so-called developmental genes also play a major role in the development of cancer.

In their molecular analyses of the stem cells and Wnt proteins of the freshwater polyp Hydra, which has only one clearly defined body axis with one opening, the researchers identified what is known as Nodal signalling in this primitive system.

“Until now we knew of this signal path only in bilaterally symmetric animals, where it is involved in establishing a signal centre for early embryonic development and left-right asymmetry. Using various pharmacological and genetic experiments, our group was able to demonstrate that the Hydra also has a Nodal-type gene, which together with the main target genes of the activated Nodal signal path, is involved in the asymmetrical positioning of the Hydra buds,” explains Dr. Hiroshi Watanabe, a member of Prof. Holstein’s group.

In the Hydra, the buds break away from the adult; in coral, another member of the Cnidaria family, the buds remain attached to the adult and form colonies with complex branches. The Nodal signal pathway is activated by components of the “primary” signal pathway that is responsible for the anterior-posterior axis (Wnt signal pathway). The Nodal pathway controls the development of the left-right body axis in bilaterally symmetric animals (e.g., vertebrates).

The Heidelberg study presents the first evidence of the existence and participation of the Nodal signal pathway in axis induction in a “radially” symmetric organism. “We assume that this was a starting point in the evolution of left-right axis formation in the bilaterally symmetric animals. Identifying just how this complex bilaterian body plan evolved opens up other exciting areas of research,” explains Prof. Holstein. These findings, however, already point to how similar the core molecular-level embryonic processes are between the simple Cnidaria and the vertebrates, including human beings.

Original publication:
Hiroshi Watanabe, Heiko A. Schmidt, Anne Kuhn, Stefanie K. Höger, Yigit Kocagöz, Nico Laumann-Lipp, Suat Özbek & Thomas W. Holstein: “Nodal signalling determines biradial asymmetry in Hydra”. Nature online (24 August 2014), doi:10.1038/nature13666

Prof. Dr. Thomas Holstein
Centre for Organismal Studies
Phone +49 6221 54-5679

Communications and Marketing
Press Office
Phone: +49 6221 54-2311

Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft
Further information:

Further reports about: Cnidaria Complex Hydra animals asymmetry humans pathway symmetric vertebrates

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>