Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Making spines from sea water

07.04.2017

How do creatures like sea urchins take up the calcium they need to build hard structures?

Some sea creatures cover themselves with hard shells and spines, while vertebrates build skeletons out of the same minerals. How do these animals get the calcium they need to build these strong mineral structures? Professors Lia Addadi and Steve Weiner of the Weizmann Institute of Science's Structural Biology Department asked this question about sea urchins, which need to extract quite a few calcium ions from sea water to build their spines. The answer surprised them, and it could change the way scientists think about the process of biomineralization.


The green fluorescent label maps the distribution of calcium in sea urchin larvae. The label shows the elongated mineralized spicules and vesicles with large amounts of calcium.

Credit: Weizmann Institute of Science

Several years ago, Addadi and Weiner had discovered that sea urchins build their spines with tiny packets of "unorganized" material that hardens into crystal when laid in place. "So the question went back a step: How do they get the calcium ions they need to make this material in the first place?" says Addadi. "Free calcium is not abundant in sea water," adds Weiner, "so they need an efficient way to extract and concentrate the ions."

To answer the question the researchers, including Netta Vidavsky, needed methods to observe the animal's cells "as is," that is, as they are in life, water included. For this the group turned to Dr. Andreas Schertel of Carl Zeiss Microscopy in Germany and Dr. Sefi Addadi of the Weizmann Institute of Science's Life Sciences Core Facilities. Very new cutting-edge techniques enabled them to observe thin slices of the cells in sea urchin embryos and then to reconstruct three-dimensional images of these cells and their intake of labeled calcium ions. "Even a few years ago, we could not have done this study," says Addadi.

The images showed that sea urchin larval cells actually "drink" seawater, taking in drops of water and manipulating the ions in the water within the confines of the cell. This is in contrast to the theory that these cells take in only ions, one at a time, through special channels in their outer membranes. The cells they observed were filled with networks of bubbles called vacuoles that collect the calcium ions, evidently creating concentrated packages of calcium for building the spines.

This method may be more energy efficient than taking in ions through channels (which the cells also did), but it presents another problem: The cells must be able to pick out the calcium as well as expel other ions in the sea water, especially the sodium and chloride. "Researchers may be busy for years to come figuring out how these cells manipulate the ions in the sea water they drink," says Weiner.

Addadi and Weiner point out that this is not the first time this type of calcium ion intake has been observed. Prof. Jonathan Erez of the Hebrew University of Jerusalem had described this phenomenon in single-celled, hard-shelled microorganisms called foraminifera a decade ago. At the time, it was thought to be a "curiosity," but finding the same process in two very different creatures suggests that it may be quite widespread. Although we do not live in sea water, even the cells that build our bones may use a similar method to obtain calcium.

###

Prof. Lia Addadi's research is supported by the Jeanne and Joseph Nissim Foundation for Life Sciences Research. Prof. Lia Addadi is the incumbent of the Dorothy and Patrick Gorman Professorial Chair.

Prof. Stephen Weiner's research is supported by the Helen and Martin Kimmel Center for Archaeological Science, which he heads; the Dangoor Accelerator Mass Spectrometer Laboratory; and the estate of George and Beatrice F. Schwartzman. Prof. Weiner is the incumbent of the Dr. Walter and Dr. Trude Borchardt Professorial Chair in Structural Biology.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.

Yael Edelman | EurekAlert!

More articles from Interdisciplinary Research:

nachricht Combating sulphuric acid corrosion at wastewater plants: Graz scientists develop new solution
23.02.2018 | Technische Universität Graz

nachricht Stealth Virus for Cancer Therapy
31.01.2018 | Universität Zürich

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>