Searching for the origin of muscles

Nature: Central components of muscles of higher animals much older than assumed

2012-06-29

(Press-News.org) A characteristic feature of most animals is their ability to move quickly with the help of their musculature. Animals that can move are able to flee, hunt for prey, travel long distances or conquer new habitats. The evolution of muscles was thus a fundamental step during animal evolution. While the structure and function of muscles, especially of vertebrates, have been intensively studied, the evolutionary origin of smooth and striated muscles has so far been enigmatic. Comparative genome and gene expression studies, performed by researchers Patrick Steinmetz, Johanna Kraus and Ulrich Technau in an international collaboration with researchers from Germany, France and Australia, revealed the origin muscle components in ancestral animals such as sea anemones, jellyfish or sponges.

Gene duplication

Phylogenetic comparisons showed that one of the crucial structural proteins of striated muscles of vertebrates, a "myosin" motor protein, originated by gene duplication. "As this specific myosin has so far only been found in muscle cells, we expected that its origin coincided with the evolution of muscle cells. We were very surprised to see that the 'muscle myosin' evolved probably in unicellular organisms, long before the first animals lived", explains Ulrich Technau who led the study.

Research in sponges …

"In sponges, that all lack muscles, the 'muscle myosin' appears to play a role in regulating the water flow", comments Gert Wörheide (Ludwig-Maximilians-Universität Munich), whose team was investigating muscle proteins in sponges together with Michael Nickel (University of Jena) and Bernard Degnan (University of Queensland).

… and jellyfish

Jellyfish occupy a special phylogenetic position to understand the evolution of muscles. They are cnidarians, an animal group that originated more than 600 million years ago, and possess striated muscles. Due to the striking similarities between striated muscles of vertebrates and jellyfish, it was so far assumed both striated muscle types share a common origin. In fact, jellyfish striated muscles also express the ancient "muscle myosin", but they lack several essential components that are characteristic for the structure and function of striated muscles of "higher animals".

This indicates that despite their striking similarities, striated muscles of jellyfish and "higher animals" have evolved independently. This study sheds light onto how seemingly complex biological structures, such as striated muscles, could have evolved independently based on very ancient components.

INFORMATION:

Publication in Nature
Independent evolution of striated muscles in cnidarians and bilaterians: Patrick R.H. Steinmetz, Johanna E.M. Kraus, Claire Larroux, Jörg U. Hammel, Annette Amon-Hassenzahl, Evelyn Houliston, Gert Wörheide, Michael Nickel, Bernard M. Degnan & Ulrich Technau. Nature (2012).
DOI: 10.1038/nature11180

ELSE PRESS RELEASES FROM THIS DATE:

Interacting mutations promote diversity

2012-06-29

Genetic diversity arises through the interplay of mutation, selection and genetic drift. In most scientific models, mutants have a fitness value which remains constant throughout. Based on this value, they compete with other types in the population and either die out or become established. However, evolutionary game theory considers constant fitness values to be a special case. It holds that the fitness of a mutation also depends on the frequency of the mutation. Scientists from the Max Planck Institute for Evolutionary Biology in Plön and the University of British Columbia ...

Taking the fate of stem cells in hand: RUB researchers generate immature nerve cells

2012-06-29

RUB biologists have deliberately transformed stem cells from the spinal cord of mice into immature nerve cells. This was achieved by changing the cellular environment, known as the extracellular matrix, using the substance sodium chlorate. Via sugar side chains, the extracellular matrix determines which cell type a stem cell can generate. "Influencing precursor cells pharmacologically so that they transform into a particular type of cell can help in cell replacement therapies in future" says Prof. Dr. Stefan Wiese, head of the Molecular Cell Biology work group. "Therapies, ...

Giant raft of data to help us understand disease

2012-06-29

Scientists at the Novo Nordisk Foundation Center for Protein Research at the University of Copenhagen have used a new method to assemble a massive catalogue of data on proteins. This gives them unprecedented insight into a process called protein phosphorylation. The research was recently published in the scientific journal Nature Communications. Postdoc Alicia Lundby, from the Novo Nordisk Foundation Center for Protein Research, says: "Phosphorylation changes are really important to our understanding of cancer and other diseases. Although the study of phosphorylation ...

Saving the Baltic Sea

2012-06-29

Over the last decade, an average of 60,000 km2 of the Baltic Sea bottom has suffered from hypoxia without enough oxygen to support its normal ecosystem. Several large-scale geo-engineering interventions are currently on the table as proposed solutions to this problem. Researchers from Lund University are calling for geo-engineering efforts that mix oxygen into the Deep Baltic to be abandoned. In the June 28 edition of Nature, researchers warn of the unforeseen effects of geo-engineering to relieve the lack of oxygen in bottom waters. "Such radical remediation measures ...

Study calls for drug trial patients to receive more information about effects of placebos

2012-06-29

Research carried out at the University of Southampton has concluded that participants in drug trials should be better informed about the potential significant benefits and possible side-effects of placebos. Placebos are traditionally thought of as 'inert' pills, given in trials to act as a yardstick or constant by which to measure the effects of new 'active' drugs, known in clinical trials as the 'target treatment'. However, placebos themselves have been shown to create substantial health changes in patients. "We believe the health changes associated with placebos ...

Gene discovery helps explain how flu can cause severe infections

2012-06-29

Scientists have discovered a new gene in the influenza virus that helps the virus control the body's response to infection. Although this control is exerted by the virus, surprisingly it reduces the impact of the infection. The findings will help researchers better understand how flu can cause severe infections, as well as inform research into new treatments. Researchers found when the virus gene – called PA-X – was active, mice infected with flu subsequently recovered. When the PA-X gene did not work properly, the immune system was found to overreact. This made ...

Wake Forest Baptist study suggests Tasers don't cause cardiac complications

2012-06-29

WINSTON-SALEM, N.C. – June 28, 2012 – Taser shots to the chest are no more dangerous than those delivered to other body locations, according to a new study by one of the country's leading experts on the devices. William P. Bozeman, M.D., an associate professor of emergency medicine at Wake Forest Baptist Medical Center, and colleagues reviewed 1,201 cases of real-life Taser uses by law enforcement agencies but found none in which the devices could be linked to cardiac complications, even when the Taser probes landed on the upper chest area and may have delivered a shock ...

Communication scheme makes popular applications 'gracefully mobile'

2012-06-29

CAMBRIDGE, Mass. -- The Secure Shell, or SSH, is a popular program that lets computer users log onto remote machines. Software developers use it for large collaborative projects, students use it to work from university servers, customers of commercial cloud-computing services use it access their accounts, and system administrators use it to manage computers on their networks. First released in 1995, SSH was designed for an Internet consisting of stationary machines, and it hasn't evolved with the mobile Internet. Among other problems, it can't handle roaming: If you close ...

Looking for the next American hyrax?

2012-06-29

If popular karaoke bars and the long audition lines for American Idol demonstrate anything, it's that people like to express themselves through song — and the bigger the audience, the better. Now researchers at Tel Aviv University have found the same trait in small, rodent-like mammals called hyraxes, indigenous to Africa and the Middle East. According to Prof. Eli Geffen and PhD candidate Amiyaal Ilany of TAU's Department of Zoology, hyrax vocalizations or "songs" go a long way towards communicating the singer's unique identity. Each one has unique songs that communicate ...

Flu immunity is affected by how many viruses actually cause the infection

2012-06-29

Bethesda, MD—Not only does the type of flu virus affect a patient's outcome, but a new research report appearing in the Journal of Leukocyte Biology suggests that the number of viruses involved in the initial infection may be important too. Scientists from Canada found that when mice were infected by relatively high concentrations of the flu virus, they not only developed immunity against the virus that infected them, but this also promoted the generation of a type of immune cell in the lungs poised to rapidly react against infections with other strains of the flu, as well. ...

Searching for the origin of muscles

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: