Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First shark genome decoded

09.01.2014
Genome of the elephant shark provides new insights into immunity and bone formation

An international team of researchers, including scientists of the Max Planck Institute of Immunobiology and Epigenetics, has sequenced and analysed the genome of the elephant shark.


The immune system of the elephant shark is simpler than many other vertebrates studied so far. The present studies also explain, why cartilaginous fishes do not generate human-like bones

© Fir0002/Flagstaffotos

Comparison of the elephant shark genome with human and other vertebrate genomes has revealed why the skeleton of sharks is made up largely of cartilage and not bone like the human skeleton and that the immune system of the shark is much simpler than that of humans. The findings of Byrappa Venkatesh and his coworkers are published in the latest issue of the scientific journal, Nature.

An unexpected finding of the immune system analysis was that sharks appear to lack special types of so-called T-helper lymphocytes, that – until now – were considered to be essential for defence against viral/bacterial infections and preventing autoimmune reactions such as diabetes and rheumatoid arthritis in vertebrates.

Despite this seemingly primitive organization of the immune system, sharks exhibit robust immune defences and are long-lived. “The structure of the immune system of the elephant shark is very different from mammals,” said Thomas Boehm, co-author and director at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, Germany. “It is obvious that sharks can efficiently deal with all kinds of infections without this particular cell type. This indicates that nature can come up with different solutions to the same problem,” stated Boehm.

What happens when T-helper cells are being destroyed can be observed in AIDS patients, who succumb to viral and bacterial infections. Up to now, it was assumed that cells are essential for an immune system. The new results are challenging this long-held notion and open up an unprecedented avenue towards the development of non-intuitive strategies to modulate the immune functions of humans.

The researchers also investigated why cartilaginous fishes, including the elephant shark, are unable to replace cartilage with bone like humans and other bony vertebrates. Genome analysis was able to highlight a family of genes that are absent in sharks but present in all bony vertebrates and are critical for bone formation. When the researchers inactivated these genes in bony fishes such as the zebrafish, calcification did not occur. This finding is a strong indication that the investigated gene family could be a starting point for a better understanding of bone diseases such as osteoporosis.

In addition, the study revealed that the elephant shark genome is the slowest evolving among all vertebrates. The elephant shark even beats the coelacanth, also called “the living fossil”, that has recently been shown to evolve extremely slowly. Therefore, the elephant shark is probably the best proxy for the ancestor of all jawed-vertebrates that became extinct a long time ago.

Cartilaginous fishes (comprising sharks, rays, skates and chimaeras) are the oldest living group of jawed-vertebrates that diverged from bony vertebrates about 450 million years ago. The elephant shark (Callorhinchus milii) is a chimaera that inhabits temperate waters of the continental shelves off southern Australia and New Zealand, at depths of 200 to 500 meters. From approximately 1,000 species of cartilaginous fishes, elephant shark was chosen as a model because of its relatively compact genome which is one third the size of the human genome.

The elephant shark genome project was funded mainly by the National Institutes of Health (NIH), USA. It is a collaborative effort of scientists from 12 international institutions, including the Max Planck Institute of Immunobiology and Epigenetics (MPI-IE) in Freiburg, Germany. Viruses, bacteria and other parasites are a continuous threat to all living beings. Therefore, most of them possess elaborate defence strategies to combat these unwanted intruders. At the Max Planck Institute of Immunobiology and Epigenetics, Thomas Boehm studies the evolution of the immune system and its development and function during lifetime of animals. For his fundamental work on development, differentiation and evolution of immune systems, Thomas Boehm is awarded the prestigious Ernst Jung Award for Medicine 2014.

Contact

Dr. Thomas Boehm
Max Planck Institute of Immunobiology and Epigenetics, Freiburg
Phone: +49 761 5108-329
Fax: +49 761 5108-323
Email: boehm@immunbio.mpg.de
Johannes Faber
Max Planck Institute of Immunobiology and Epigenetics, Freiburg
Phone: +49 761 5108-368
Email: presse@ie-freiburg.mpg.de
Original publication
Venkatesh B et al. (2014)
Elephant shark genome provides unique insights into gnathostome evolution
Nature, January 8, 2014. doi:10.1038/nature12826

Dr. Thomas Boehm | Max-Planck-Institute
Further information:
http://www.mpg.de/7696371/shark-genome?filter_order=L&research_topic=

More articles from Life Sciences:

nachricht Immune Defense Without Collateral Damage
23.01.2017 | Universität Basel

nachricht The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>